The “please sync again” message is due to some discrepancy between the count of files on your local device and AnkiWeb - around 10 files. I’d start by repeating the logout-and-sync steps again while you have all add-ons disabled, to rule them out as contributing. Some add-ons dump files in the media folder, and depending on when they’re being written, it may be causing this.
Please note that this won’t help you recover any media files you’ve lost - it will just prevent that message from showing at the end of a sync.
I can also restore any media files you have deleted from AnkiWeb in the last month (~800). This will only help if the recently-deleted files are the ones that you’re wanting to recover.