I have two different mobiles (Samsung S21FE and OnePlus 9 Pro) with the same behaviour:
after replacing the SIM anti-theft locked the phone. But instead of asking for the defined PIN is asked me to input the eset home login password (which is very annoying because it is a long and complicated password).
When i try to force an anti-theft lock by entering wrong screen unlock codes several times it asks me for the PIN (as i would expect from the anti-theft settings).
Is this an expected behaviour?
In one case that lockup came after the phone made a firmware-update while i was on vacation. I could not use the phone until i was back at home to get my eset home password. Currently my only solution is to disable that sim-monitoring.