Jamroom triggering high CPU on hosting
Using Jamroom
You have Apache resource limits in place, so you're just running in to that. You could just try restarting your web server to see if that helps, otherwise there isn't really anything we can do for you here other then you can upgrade your plan to one that is not resource limited.
As for APCu if you see that error in the Server Check then it means the "apcu_add" function does NOT exist in your install:
https://www.php.net/apcu_add
Regardless of what your hosting panel is showing.
Let me know if that helps.