Not sure if it helps, but I've found this bit of code which is GDPR related.

Bit beyond my understanding, but there's a section halfway down about analytics which might be causing it?

<script type="text/javascript" async=1>
	;(function(p,l,o,w,i,n,g){if(!p[i]){p.GlobalSnowplowNamespace=p.GlobalSnowplowNamespace||[];
			p.GlobalSnowplowNamespace.push(i);p[i]=function(){(p[i].q=p[i].q||[]).push(arguments)
			};p[i].q=p[i].q||[];n=l.createElement(o);g=l.getElementsByTagName(o)[0];n.async=1;
			n.src=w;g.parentNode.insertBefore(n,g)}}(window,document,'script','//cdn2.editmysite.com/js/wsnbn/snowday262.js','snowday'));

	var r = [99, 104, 101, 99, 107, 111, 117, 116, 46, 40, 119, 101, 101, 98, 108, 121, 124, 101, 100, 105, 116, 109, 121, 115, 105, 116, 101, 41, 46, 99, 111, 109];
	var snPlObR = function(arr) {
		var s = '';
		for (var i = 0 ; i < arr.length ; i++){
			s = s + String.fromCharCode(arr[i]);
		}
		return s;
	};
	var s = snPlObR(r);

	var regEx = new RegExp(s);

	_W.Analytics = _W.Analytics || {'trackers': {}};
	_W.Analytics.trackers.wSP = 'snowday';
	_W.Analytics.user_id = '18134955';
	_W.Analytics.site_id = '772321040437243093';

	// Setting do not track if the GDPR cookie is not present. This is then checked by the snowday initializer
	// to set tracking decisions. https://github.com/snowplow/snowplow-javascript-tracker/blob/2.6.2/src/js/tracker.js#L1509
	window.doNotTrack = document.cookie.indexOf('gdpr-kb') === -1 ? 'yes' : null;


	(function(app_id, ec_hostname, discover_root_domain) {
		var track = window[_W.Analytics.trackers.wSP];
		if (!track) return;
		track('newTracker', app_id, ec_hostname, {
			appId: app_id,
			post: true,
			platform: 'web',
			discoverRootDomain: discover_root_domain,
			cookieName: '_snow_',
			contexts: {
				webPage: true,
				performanceTiming: true,
				gaCookies: true
			},
			crossDomainLinker: function (linkElement) {
				return regEx.test(linkElement.href);
			},
			respectDoNotTrack: document.cookie.indexOf('gdpr-kb') === -1
		});
		track('trackPageView', _W.Analytics.user_id+':'+_W.Analytics.site_id);
		track('crossDomainLinker', function (linkElement) {
			return regEx.test(linkElement.href);
		});
	})(
		'_wn',
		'ec.editmysite.com',
		true
	);
</script>

This is unfortunately something expect with GDPR. Because Google tracks with cookies, if someone declines to let cookies be set when visiting your site they will not be tracked.

Thanks for the reply.

Is there a way around this? The numbers haven't dropped by 90% on the 'Weebly stats page' so presumably it is counting people who haven't accepted cookies.

In fairness, the clumsy implementation of the cookie banner text, placement, button options, and display parameters has a lot to do with whether or not cookies may be set. 

Contrary to only affecting EU clients, if a North American visitor doesn't see the cookie banner displayed (when set to EU only), then they cannot opt in, and, at least from the cookie opt out box you have available to add to the site, it shows that their cookies are never set, leading to a loss of that traffic as well.

Here is the thread where this is discussed: 

https://community.weebly.com/t5/Community-Feedback/Cookie-Opt-Out-Box-Weirdness-Showing-an-Opt-Out-t...

When will this be seriously looked at and fixed, @Adam & @Bernadette? 

Same problem here though this is quite an old post. In January my site was getting around 3000 page views a month.  It has dropped every month since then and was only around 600 views in August.  I keep trying to explain to support but I don't think they realize how devastating this is to people who are trying to grow their brand and business.  I am sure this is to do with blocked resources (44 of my 52 pages now), poor user experience when they can't get the pages to load, as well as GDPR from May onwards.  September is looking even more disasterous.

I have been using Analytics a lot over the last few days and have been noticed huge page download times.  I set the graph to see if there was some corellation. I have done several benchmark tests and used website health checkers etc.  They all highlight problems.  One even says I don't have a robots.txt in my root directory.  Confused!  All these tools are liars apparently!

In my experience it's not too unusual to see a decline in traffic after the first few months of the year; I think it's just seasonal behavior from people online as the weather starts to improve. That said, GDPR absolutely did affect people's stats from May onward since Google Analytics tracks by cookie - there simply aren't as many people being tracked.

I don't have specific dates, though it is very possible that those three spikes were brief periods of downtime. Google can check sites multiple times in a day so even brief outages can show up. Interestingly, it didn't seem to have much of an effect on tracking, which suggests they weren't long enough to really impact that.