Troubleshooting an alleged issue with a scheduled task

Hi, I am trying to figure out the root cause of a OOM error (out-of-memory) on a Cloudlinux server.

Every night (approx. 1:29am) I see this:

Oct 15 01:25:08 server lfd[187588]: *Excessive Processes* User:username Kill:0 Process Count:148

(it's always the same username, WordPress+Woocommerce shop)

I haven't no access to this WP installation, so I am analyzing this issue out of the box.

Which tools can I use to investigate this?

I activated WP's debug, but debug.log is full of this lines:

[15-Oct-2024 08:10:54 UTC] PHP Warning:  Undefined array key 3 in /home/username/public_html/wp-content/plugins/loginpress/custom.php on line 2058
[15-Oct-2024 08:10:55 UTC] PHP Warning:  Undefined array key 3 in /home/username/public_html/wp-content/plugins/loginpress/custom.php on line 2058
[15-Oct-2024 08:10:55 UTC] PHP Warning:  Undefined array key 3 in /home/username/public_html/wp-content/plugins/loginpress/custom.php on line 2058

Any suggestion? Thank you!