@stanwood Thank you anyway for your support! I will contact XDA people to understand why your RN7 has gps and not mine. Have a nice day (night?).

SOLVED

I read through all the GPS topics on the Telegram channel, and understood that 'test_gps' could report "GPS interface not found" even when the GPS is working!

I did new tests, left my house, waited a few minutes outside and found that the GPS was working (Pure Maps or Google Maps). And indeed, in this state, 'test_gps' keeps saying "gps interface not found"... I thought it was trustworthy, but it is not!

So everything is fine, now.

Thanks to @Josele13