Hi there.
Usually, my web is blazing fast - it loads under 2 seconds. And somethimnes, once in a few days, it loads extremly slow - 30 or more seconds. Its unusuable during that period, which last 30 minutes or so.
Its https://preporucamo.com
I cant detect what is happening; my hosting is premium quality and price, they says its all good.
GTmetrix looks like that
They usually do 
When this happens, have you verified it does not also occur when going directly to your server, bypassing Cloudflare?
From your screenshot it seems the issue is static resources, not even the page itself.
Thx for answer. somethimes, waterfall slows only first byte is watining, like 20 seconds. Sometimes, GT metrix and Test With Google shows extremly slow loading, but its not for me, working blazing fast. And vice versa. I will try to turn on maintence mode next time I notice this. So far, it looks totaly random. I checked on C Panel, there was no problem with resources (CPU/RAM of server)
So you experience the issue only with these test sites, not you yourself at that very time? Could it be an issue on their side then? Have you got any such reports from other people?
What is basically necessary is to make it somehow reproducible. Otherwise its debugging in the dark 
Well, not only test site, I can feel it also. So I complain to my hosting, they investigate and fee it also
In that case the first step should be to check if you can reproduce it by connecting directly to your server.
Right now. GTmetrix is good, Testmysite is bad. Its usually 4 - 5 seconds. To me, site is working fast
By adding your server’s IP to your hosts file (along with your www host and naked domain), waiting until your browser has forgotten any cached IP address, and opening your site again (and making sure via developer tools that it actually took the overwritten IP address).
