Dear Another Elk,
I really would like to acknowledge you for your patient help. I kept trying, different wifis, different USB ports, more factory resets and many more attempts to reinstall in the emergency mode (it never worked though, always the same problem described above).
Then, one day last week, I was just waiting for someone in his office, connected to his wifi and tried again, just out of boredom. And all of the sudden, it worked. I got all my apps back within two days, even when later connecting elsewhere. No idea what eventually fixed the problem. I swear, I am not making this story up.
The month living with a dumb phone again was cool. But having these functions back is practical. So I am really grateful for the help received here.
Best wishes towards the new year!