Thank you for checking on your end, Bernadette. The only thing I changed in the HTML/CSS was the size of the container, to enlarge my post slightly:

.container {
  width: 100%;
  max-width: 980px;
  margin: 0 auto;

I changed the max-width: from 960px, to 980px. I haven't altered anything else in the code. Although, I have installed various new Apps recently. I'm fairly certain this issue was present, before I made any of those changes, however. Which is why I tried the Disqus option, and then removed it.

It's interesting I can duplicate the problem, on two different computers, without me logging into my account with one. And it seems to apperar in both Firefix and Chrome. What the two computers do have in common however, is Ubuntu OS.

More interesting. I just tried it on my android phone, and the same problem occured. I couldn't check the box. So it cannot be an issue with Ubuntu OS, on the other two computers.

So it occurs to me, after checking on different devices, what you meant by, "something in your custom code that is causing the error", is it will happen to every device, which uses the original blog I created. Only on the "copy" site, you were able to check the box. So how do I determine what is interferring with the checking box function, on my end? 

I reversed the code to the original, blog post size (960px) and it didn't make a difference to successfully checking the box. So I reverted it back to 980px. It has to be one of the weebly Apps I installed, possibly?

Oh, yes, that could be possible. I just remembered that when we make copies of sites blog content and purchased apps will not copy over. Have you added any type of code to the blog itself? When I made the copy site I just created a new blog post with basic elements. 

I haven't added extra code. But did another test blog post, yesterday, and it still wouldn't check the box. I'm ready to go live with my site, but this is the one issue holding me up. If someone could actually look into the Apps on my site, to see if there is a conflict, it would be appreciated. There's nothing I can do from my end, as I haven't written new code; just the 20px size alteration I mentioned earlier. 

Back to Top and Blog Image Card, are the two Apps I've installed. The Blog Image Card, links to the Blog page I nominate in the URL. The only thing I've done differently, with that App, is install the same URL address for both the blog post and categories. Just to ensure the reader reaches the destination of the blog post I nominate. I recently tested if that was the issue, by nominating the correct Categories URL address, but it still made no difference to successfully checking the box.

I would really like a solution soon, as it's holding back my anticipated date to go live. I've created interest on my other blog for the changeover, and others are starting to ask me about who I went with, and how my experience is going. 

The only thing I can suggest is reverting your theme to a standard Weebly theme on your original site and testing to see if the box works. I know you only made a small edit to the theme, but if you are manually removing the code or editing back to what it was before, your theme is still considered "custom". If you revert to a standard Weebly theme and still have the issue we can escalate a ticket to support for you. 

When you say, "reverting your theme to a standard Weebly theme on your original site", can I select my existing theme, and it will upload the original code? I would like to stay with the original theme. Or are you suggesting I attempt a different theme, altogether? Thanks.

Yes, you can select the original one you were on before editing the code. You can tell if you are on a custom theme by clicking on Theme>Change Theme>Custom and looking for a checkbox next to "using". 

When you are on a "standard" theme you will see the checkbox under the "Recently Used" tab. 

Thanks for the clarification, it helped navigate how to change themes properly. I've tried Cento and Unite themes now, before reverting back to my original Haberdasher theme. I was sure to publish the site between each change, to make them live again. I even closed down my browser, afterwards and reopened it. Habberdasher theme is now checked, as "using", under the Recently Used, tab. Unfortunately, all these steps, failed to rectify the box checking, successfully in the blog comments section.

To be clear, the box didn't check in comments, on any of the new themes I published either. I checked if they would. 

Interesting new development. Sent a dummy comment and checked the box - despite not seeing a tick in it. But the box had an orange border around it, like I engaged the service, regardless. I received an email notification from Weebly, at two different email addresses, to suggest the check box was successful. Despite the tick not appearing, the notification service was engaged. If you could get back to me on this, it would be great.

Secondly though, and may be the deal clencher for me - as I'm about ready to walk away from the default. Is there a limitation to how many replies are allowed to one comment, before the "reply" button fails to appear again? I could only get two replies, to one comment. Wondering if this is an issue, attached to the mysterious missing checkbox, that works. Of if the limitation, is just part of the default set-up?

I figured out what I meant by comment limitation. It was a user error, between the "reply" and "submit" button. An easy mistake to make, when the buttons have exactly the same colour and design. Especially when writing short comments. I was pressing reply instead of submit, making the comment box disapper. I thought it had published, but didn't. Because I didn't really press submit!

I also figured out how to use the reply buttons effectively, to embed them in one another. So you're right, it's not a comment limitation. Just a hard design to navigate. I'm thinking of new readers, who may turn away at the difficulty of navigating the comment box.

I would like to request a suport ticket, to resolve the checkbox issue in the comments default. I don't know if it's limited only to the comments section, or an underlying problem with other code, which could interfer with other options. Like setting up forms, which require a checkbox feature, in future. I'd like to eliminate it as a problem. Can you please give me an estimated time to resolve the issue, so I know what to expect. Thanks.

We really don't have a way of providing time frames for completion. You can submit a ticket here: hc.weebly.com (the contact button will be at the top or bottom of the screen) but again if support sees a custom theme or even embedded code on the page itself they will not be able to assist. Adam will be in tomorrow and I'll see if he can take a look. He may notice something more obvious that I'm missing. 

I appreciate if Adam can take a look. I'm a little confused however, that I can submit a ticket myself. Because you said in an earlier comment: "If you revert to a standard Weebly theme and still have the issue we can escalate a ticket to support for you. " Is that not the case now? I figured using the term "escalate", meant I got put up the list, because I already went through a preliminary check, first. 

Sorry, I may have misunderstood your "to embed them in one another." comment. I thought you meant you were using the Embed Code element that would also be considered custom code. I'll have Adam take a look tomorrow. 

I can see the confusion, "embedded" can cause, when it comes to an issue about custom code, lol. I'll consider using a different word, in future.

Appreciate your patience. Hopefully Adam will be able to fix it.  

Thanks for helping bring about a solution, Bernadette. As way of further feedback (if it helps Adam) I installed a Newsletter form on the "home" page, and was able to successfully check the box. Also, installed a Newsletter form, in the side bar of the blog post, also at the end of the blog post. Those two were successfully checked, with a tick as well. So it looks to just be an issue with the comment box.

I don't intend to leave the Newsletter forms there permanently, but thought it might help Adam test the system (if he needs to).