When keys are created with sq, changing their expiration date with GnuPG doesn't seem to work

Reported via IRC by user "dk_", Sep 15th, 07:45 CEST

i'm [..] wondering why keys generated by sq ( 0.27.0, sequoia-openpgp 1.10.0 ), cannot be renewed by GnuPG?  I tried it multiple times with ed25519 and rsa4096 keys generated by sq, and GnuPG, neither 2.3.3 nor 2.3.7, were able to extend their expiration. Is this a bug, an expected behavior, or i did something wrong? 

No error message at all. I just do "save", but the expiration date on the key doesn't change.
I also tried using `gpg --quick-set-expire`, but it also didn't update the expiration date, without any error message.