Upgrading 5.2.1 -> 5.3.1 leads to errors with Composer

[BaliDave]

When I upgraded to 5.3.1, a number of pages -- but not all -- with ads now show the message:

"Composer detected issues in your platform.  Your Composer dependencies require a PHP version ">=7.2.5"

and that is the only thing that appears on the page.

I recently upgraded to PHP 7.4.27 from 7.1 and simultaneously from running Apache as a php-module (user "nobody") to as a CGI module (using my username).  I'm on a server using cPanel and the PHP 7.4 is effected by using their EasyApache selection for the site.  All other parts are fine with 7.4 including WordPress and phpList.  Note that cPanel itself is using PHP 7.1 and I cannot control that.  Both phpinfo and php -version show 7.4.27.

Any ideas on how to debug this?

One other piece of information that MIGHT be relevant: the current 5.2.1 version is running fine, however I noticed in the var/cache directory about half of the delivery_xxx.php files are owned by nobody (600 perms) and the other half are owned by my username.  And chown'ing and chmod'ing these "nobody" files is soon overwritten, and I'm back to previous state.  I tried rebooting the server to see if these were just from some left-over process/thread running under Apache, but still get the same behavior.  I don't understand how now with php running as a CGI module with my username, files with owner "nobody" can get created.

Again note that this bit of info may NOT be relevant to my problem above.

[BaliDave]

I'm still stuck and can't do the upgrade to 5.3.1, and 5.2.1 is still apparently invoking some code running as "nobody" instead of my username, and generating files in /var/cache directory.   The upgrade attempts wind up with Composer seeing cPanel's 7.1 version of PHP instead of my 7.4 version. The mystery is how does RevAds invoke a "nobody" process, when PHP is running in CGI mode as my username.  All ideas welcome, please.

[BaliDave]

The problem has "disappeared", tho for unknown reasons.  5.2.1 was still problematice with "nobody" processes running alongside those with my username, but this time (4th try), the upgrade worked.  Gremlins gave me a reprieve.?