Could not execute script and 500 error?

Question

Apache HTTP Server

I encounter an error: Error 500, it works 1 out of 50 times (randomly), I thought for a long time why it was, and found the following errors in the Error log:

[Sun May 05 03:49:02.086176 2019] [:error] [pid 215322:tid 47551730546432] [client 11.12.13.92:0] SoftException in Application.cpp:630: Could not execute script "/home2/user/public_html/website/script/script.php"

[Sun May 05 03:49:02.086299 2019] [:error] [pid 215322:tid 47551730546432] [client 11.12.13.92:0] Caused by SystemException in API_Linux.cpp:458: execve() for program "/opt/cpanel/ea-php56/root/usr/bin/php-cgi" failed: Resource temporarily unavailable

[Sun May 05 03:49:02.086325 2019] [core:error] [pid 215322:tid 47551730546432] [client 11.12.13.92:0] End of script output before headers: script.php

Tell me what does that mean?
Many may think that the code is written crookedly? - No, I think it's stupid, everything is fine in the code and it works out as it should during tests, in addition, exactly the same errors fall on other scripts that were not written by me, but by other developers, and these scripts work on hundreds of sites.
The error cannot be thrown randomly, it is clearly thrown in some cases, but I can't figure out which ones exactly.
I turned to the hosting, they don’t really want anything further than changing the php version and shrug.
I use cloud hosting and have 17 cron tasks running 1 time per minute. I googled and stumbled upon a topic with a similar problem, and as the author says, the error is caused if 3 people do something on the site at the same time and they say its host said that 25 processes is the maximum that they can do on a cloud host, I think maybe something similar happens to me, when more than 25 processes are running, it gives error 500?
If so, what are the solutions to the problem? The host is paid for until 2020 and no one will return the money, so I can’t consider options to switch, leave, etc., and no one will raise the limit for me, this is a cloud host and everyone has the same conditions.
ps Perhaps if I transfer 2-3 Cron tasks to another hosting (VPS for example) it will make my cloud hosting work easier?