It's not the 'same error' and, yes, does indicate a environment/server issue .... not Moodle.
See by one of your screen shots a php.ini. Could be something in there.
Wonder what else your server provider is running with PHP ... Shoshin? You can see many settings for PHP by using the PHP Info link from Moodle Site admin Server.
Could do this as another test:
upload one of those .mbz files to moodle code root ... do not put the file in any folder. Then, with any browser, attempt to access that file directly with browser. That might produce a different error but then it's just apache as you've taken PHP and Moodle out of the test.
Do not leave that test .mbz file there after testing.
Looks like you will have to re-open ticket/communications with your provider.
Can you see any apache error logs? Check those.
'spirit of sharing', Ken