Weird: manually added data auto-deleted?

Hi everyone,

For a project of mine, I’m trying to add a simple thing: a label with two TexTMagic displaying a score e.g. “6/12”.
-The 12 part comes from the total answered questions so +1 is added every time a user answers a question.
-The 6 part comes from the correct answered questions so +1 is added only sometimes, when user answers correctly.

Here is how the display looks like:
Capture d’écran 2021-04-07 à 23.57.26
Capture d’écran 2021-04-08 à 00.04.59
The " / 12" part displays correctly. However the “6” part in this example does not display.
This does not seem to come from the mechanics of it (the +1 only sometimes) because the score which is based on the same action works correctly.
Also, what surprised me is that I tried to manually add data to test the display and when I run it nothing is displayed + the data disappears from the database (only the “6” part here).
I thought that maybe it is not initialized correctly so I set up an automatic field with this variable set to +1 but it won’t do anything.

Have you encountered such a thing?

Any suggestion on where the trouble might come from?