I have seen numerous threads reporting this issue dating from September 2020.
Now it hit me with the latest Fairphone update: No more incoming callers are displayed, unless I disable 4G/LTE. But this cannot be seriously the solution since 1 year ago for people experiencing this problem.
Especially since Vodafone currently offers to me (in my hometown Dusseldorf) only 4G or 2G. When I disable 4G I would have to use EDGE!
The same here since sept 10th. Tried several setting-changes with no result. I work with two sim cards. One shows the name/number of the caller, the other doesn’t. What can I do???