On 18 Oct 2023, at 21:45, Patrick Dupre via users <users@lists.fedoraproject.org> wrote:

 Failed to parse Signature Packet
     because: Signature appears to be created by a non-conformant OpenPGP implementation, see <https://github.com/rpm-software-management/rpm/issues/2351>.
     because: Malformed MPI: leading bit is not set: expected bit 8 to be set in   101000 (28))

I read the issue 2351 and it is saying that there are RPMs that where signed by a buggy gpg implementation.

Apart from dnf remove of the old RPMs you have installed I'm not sure what to suggest you do to fix this.

It is odd that your other system is fine. Are there any RPMs that only the problem system has installed?

Barry