I've tried on my installs, creating another generic user and it can see all the modules, extensions included.
Then I saw in "man php" the -n option, that starts php without reading the .ini file and launching it like this it shows only the builtin modules.
I think in your case is not finding/reading that file (so he doesn't activate extensions): maybe you have to launch it specifying with the -c option the location of the php.ini.
obviously, I would check also if your user can read it making him issue a
can be also some directory permission are changed from the default (you tell us on one machine it works ok: I think a clean slack 12.2 don't behave like that -I tried on -current).