Unconsistent value of a Ref

[peremayol]

I am testing AppSheet with my database of coins.
The database is in several sheets of one Google Spreadsheet.
Each Mint (city) includes a Ref to one Territory (ID_Territory) where the Mint is located.
In the view for the list of mints I have grouped them by Territory, so in the group Europe you will find the Mint of Barcelona (Barcelona is in Europe ). So the Ref to Territory seems to be working very nicely.
Now comes the very strange thing happening: When I click the Barcelona Mint to get further detail on this mint in the Territory field the value Europe also should appear. But it doesn’t! Another different territory appears (Asia Persica)!
Any idea what might be happening?!
Screenshot 2020-10-20 at 20.32.19|690x169