HI Philippe
Sorry I just got my head around the problem you are having.
The profile page appears to be loading through a router - ‘Update’ right?
The logic in your router is what we probably need to see to help you debug this.
My guess is that there is a disconnect between the wixUsers.currentUser.id and the ids stored in your TeacherProfile data collection. There was a similar post by another developer where they we finding multiple records with common key data (not necessarily the id but they were looking at other info like email address) in their database which resulted in their validation logic failing.
I would look at the router code and database records with the id and see if this is an issue. If you share the code in Update that would also help us help you further.
What data is added to the ‘TeacherProfiles’ data collection and when, how it is subsequently used or updated. So for example
How is the original TeacherProfiles data collection record created?