Thanks for your help with this @anonymous20. I didn't think that less than 10,000 monthly views was that heavy either. Here are the stats that I can see in my cPanel:
I think I've reached my limit on my ability to troubleshoot. I'm going to look at other hosting plans.
Tim: the 100% CPU usage is strange. Something is wrong. The rest is just fine (entry processes etc).
And yes, 10.000 hits is not much, still i can't say for sure because it also depends of what exactly you serve to the users. I mean could be heavy stuff.
And with PHP 7 and some caching plugin CPU 100% is hard to reach.
Good luck !
I was heading down the wrong path here.
This is the temporary solution that I'm now working with:
https://wpforo.com/community/how-to-and-troubleshooting-2/high-cpu-usage-on-forum-pages/#post-18780
Is your DEBUG.LOG of Wordpress totally clear ?
This
define( 'WP_DEBUG', true );
is also needed, i guess you added it ....