I have an issue with a WordPress website I made: https://j-martini.com
Sometimes (generally the first time you access the website), the time before even HTML gets loaded can be very long (for example on this capture, 8s: https://postimg.cc/qgR0xqKm
I have no idea where the issue is coming from and since every time I test the website with tools such as GTmetrix I get a good result, I don't how to monitor the issue.
I contacted my hosting service, Scaleway, because I'm suspecting a slow server, but they're trying very bad to not help me at all. Even if it doesn't come for the server I kind of hoped that they could help me figure out where the problem is, but apparently not.
Any help would be very appreciated!