PIN code when I want to unblock

You could try whether turning off the phone, removing the SIM card and putting it back in does something in that regard.

How old is the SIM card? SIM cards are peculiar, they can degrade and develop problems over time. If you have a different SIM card at hand or if you can borrow one, you could check whether the issue persists with a different SIM card.

It depends on how you got to the current version and on more detail about the current version.
If you simply updated with the Updater in Settings …

If you installed the current version yourself, it would depend on whether you are on Android 9 or 10 now, and whether you are on release channel dev or stable.
All there is to know about this is given in Settings - About phone - Android version (tap on it) - /e/ version.