Lost an identity card in 2018 and subsequently got a new one. The old one of course got blocked.
However, when using my new one, an alert pops up referring to the old one, which border control occasionally reacts to (they then normally more or less tell me about it if we have a common language, but it could be the reason for me being held for an hour in Milan recently, under the false pretext of me allegedly not being allowed into Italy passport-free if arriving directly from Ukraine).
According to a specialist at the Swedish police, it's because the systems recognise my name and date of birth, but don't take into consideration the new document number.
Now, I imagine if someone were to find my old ID and copy and sell to an illegal immigrant, they would either copy all the data exactly, or alter all the data.
In what case would they alter the document number but leave the other data intact?
What it boils down to is: why would using my current ID trigger an alert due to my old one?
I don't know if using a passport would have the same effect - I'll reply and ask that after hopefully getting feedback from here.