Android 13, Samsung Galaxy A73, the latest version of the app from the Google Play (at the moment).
I experienced the problem two weeks ago.
To fix it, I created new folder using web interface, and assigned it as the default there. Plain folder, no stacks/notebooks.
Regarding the age - the symptoms were exactly the same as described. The googling confirmed that the problem exists for year at least. Once I fix it, I forgot about it. I guess, other users do the same. Only the remainder in GTD system pushed me to answer here.