In T5436#148656, @cnp1234 wrote:

I added "disable-application piv" to ~/.gnupg/scdaemon.conf and the behavior went back to pin caching working as before. Since I don't use PIV, this is an acceptable workaround for me.

Ah, yeah, that worked. I was confused by the fact that I already have the bang in my .gnupg/gpg.conf, and got a warning when explicitely passing it to GPG.

I run in the same issue as PRab whenever I suspend or hibernate my machine. The
machine as Broadcom BCM5880 with a smart-card reader, so I cannot unplug it.
Quickest workaround is to kill/restart scdaemon.

Is there/could there be a command that could be sent to scdaemon via the agent
so a reset could be triggered? It should be easy enough to line that up as part
of the resume scripts.

So, I understand this can't be fixed in software?