OpenPGP in Thunderbird

I noticed something very strange these days.
A collegue send me a GPG Pubkey and I tried to import it as ASC in TB which itself works fine, but when the key was expired and got extended (before) the import may work but you can't send anything to it.
Even deleting the subs with gpg doesn't work, TB still refues to see the Pubkey.

Idk if other people these days having such issues too, but it sucks.

Also trying to work around by tweaking the time of the System (or TB itself) its just nonsense and doesn't work. Publishing it to a Public Key Repo doesn't solve the issues too.. even after like I already stated above, removing the sub key (the expired one)