I tested by logging in with his user and when I get to the homepage his actual photo appears for a fraction of a second, but it gets switched with another one that's not this user's profile picture. It only happens on this user and only on the homepage.
We've tried changing his profile picture or deleting it, but no matter what the unintended picture always ends up showing.
This looks like a hack to us, but can't find the way to solve it, any recommendation??
First of all, don't think it's a hack ... if one thinks about it a minute, why risk getting caught messing with a system provided by any entity that provides grades/compentencies, etc. that would affect a students future (unless you are a K12 entity). But even then, if one had the knowledge to hack, why not go after grades?
Now, I could write up a great/long explanation of users pics (technical) but rather than do that, how about we try what might be a simple fix ... purge the moodle cache. First through the Moodle Admin UI.
Also a suggestion ... sounds like your server might be in a beginning stage of file confusion ... suggest installing moosh. A couple of the moosh CLI commands check the 'health' (for lack of a better term) of the file system. Remember that what you see image wise in a Moodle is a combo of meta data (mdl_files table in the DB for the moodle) and what actually exist in the sea of files in moodledata/filedir/ (which in itself is worth several paragraphs).
Let's hope it's simple!
'spirit of sharing', Ken
Are Gravatars enabled on your site? If so, Moodle will be pulling the profile picture from the Gravatar site rather than using the default profile image.
Check at Site Admin > Users > Permissions > User Policies, and also see https://docs.moodle.org/36/en/User_policies#Enable_Gravatar
The image that gets shown is in fact from a political party's official website, which looks like a prank to us