Google Page Speed Insight Shows In-Consistent Results

I have a wordpress website running and i am using W3Total Cache Plug-in to make the site load faster. When i scan the site in Google Page Speed Insight, i noticed i am getting in-consistent scan results. I have a Facebook Messenger chat floating on the webpage and a google map. Since these two gave me Reduce the impact of third-party code Warning i have made changes so that these two will be loaded only after the DOM has loaded completely. Actually i have used jQuery SetTimeOut for this. I actually managed to remove the warning from the result by doing this. But now and then i noticed the same warning coming back in, even if i have made adjustments. if i scan the site two or three times frequently the warnong may go off, but will be back again once i try after a while.

These are the result of frequent scans. Do you guys have any idea about what would be going wrong here ? I spent a lot of time searching but couldn't get my head around it.

From what I can see you have set the "delay" to 3 seconds on Facebook Messenger chat. However your site takes a lot longer than this to load the initial content.

Your site will often not have loaded the "above the fold" content within 3 seconds due to things like network latency, load on your server etc.

For this reason the Facebook Messenger chat script is getting loaded at a point where the CPU may or may not be busy. For things like "Total Blocking Time" this is important as that is listening for when the CPU has it's first quiet period to work out when the page is usable.

For working out "impact of third party code" it is looking at when the CPU is working while trying to render the "above the fold" content, hence why sometimes it shows as an impact and other times it does not as sometimes your above the fold content has loaded sufficiently before the Facebook Messenger is initialised.

Additionally you have to consider when your main JS file containing the timeout is loaded, sometimes it will be loaded sooner depending on latency etc. so this will impact the time the fbDiv is added as well.

There is a lot to cover so to simplify the answer (as there is an awful lot to explain as to why this happens) is to increase the delay on Facebook Messenger or only have it load on a button click.

For example you could have a button that says "chat with us" and then use the click event to load facebook messenger (and hide the "chat with us" button). This would be my recommendation

Alternatively looking at the load speed on your site you could set the delay to about 7 seconds and it would then (probably) be consistent.