Guys, this issue will be Service provider related. I have two S10, same Model Number (SM-G973F/DS), same Software latest version (G973FXXUFHVE1), working on same network (Vodafone, Spain) so unlocked. One has Caller ID and spam protection ON but you cannot turn off, other is the opposite. Switched OFF and you cannot turn off.
But the Service provider software versions are different (CSC code):
Protectoin ON: .....AMO/AMO,AMO/AMO (Spain)
Protection OFF: .....BTU/BTU,BTU/BTU (Great Britain)
Maybe that's the key... i'm going to try to change BTU version to AMO on my second phone and keep you updated.
Guide how to change the Service provider (CSC code):