Yesterday, I enabled the “Browser Insights” feature, by clicking the switch to “On”
However, I don’t seem to be getting any sort of browser insights for my website at all, it says “No data exists for this time period”, the same error happens for any time period, even though I refresh my page etc.
What should I do?
Check again while recording the network traffic with your browser’s dev tools.
Cloudflare injects a script to run those measurements. This is detected by ad blockers or probably blocked by your server’s content security policy.
This is what it looks like:
Okay, my apologies
I should’ve tried this before making the thread, but I fixed it by Purging all Cache in the Cloudflare dashboard , and then CTRL-F5 reloading the page
That would have been my next suggestion.
Glad to see it’s working now 
