So guys, I've been using Bitcoin Core 0.20.1 and now I had to sign a message to be able to verify an address when buying some BTC.. part of a KYC process.

I have two type of addresses in my wallet. One starting with "3"  and one with "bc1"

I expected the first one not to work since its a sort of legacy address.

When signing with either of them I get the following error "Address does not refer to key (code -3)"

So now it seems that no matter what type of address I create from within that same wallet, none of them are able to sign messages...

Am I missing something or does this function simply not work? It seems Electrum can do it just fine.