worpress error load-styles.php

hello, on my server i have some wordpress website with the same problem. wp-admin dashboard does not correct load with cage_fs enabled ( CPU fault, 1 core for account, load on server is around 3, i have 8 cores ) script load-styles.php return 500 . disabling case_fs it works. website is consuming to much CPU loading wordpress dashboard and it faults. this is recent problem, 2 or 3 days ago we worked well on it. after some test i found that disabling opcache website works good and does not consume all the CPU core. on one website i have fix it optimizing with a plugin (WP_OPTIMIZE) could please help me to identify the nature of problem? thanks