Sometimes on Windows the GnuPG System "hangs" by GnuPG System I mean both OpenPGP and GPGSM. So it's likely to be related to the gpg-agent or shared files like the pubring.
All further operations spawn a new gpgsm or gpg process but do not finish. This can happen as soon as GpgOL / Kleopatra starts leaving the whole system blocked until processes are killed.
I've seen it in the past multiple times and T4248 is related and probably the same. The best way to reproduce it seems to be a bulk import of certificates. They do not have to be secret as T4248 describes. This needs to be fixed as it happens multiple times per day / week in larger deployments.again" is a restart of.
Highest prio as this seems to be a deployment blocker and I will work on it with the highest prio.