Actually pinentry has the same behaviour, so this might be a general problem, if one form input field is changed.
It also applies to clicking on other form elements.

To reproduce:

1. Create a new certificate with passphrase
2. On pinentry
   1. Enter the passphrase in the first input field
   2. Click on the second input field (Repeat) -> needs 2 clicks
   3. Enter the repeated passphrase
   4. Click on the first input field -> needs 2 clicks
   5. Change the first first passphrase again
   6. Click on "show passphrase" button -> needs 2 clicks
   7. Change second input field
   8. Click OK -> needs 2 clicks

This isn't reproducible on Linux. (Tested with a Yubikey but that should really make no difference.) Maybe a regression of our Qt patches.

I can reproduce on windows. It's not that the Button itself needs to be pressed twice, *something* in the dialog needs to be pressed before the button reacts. So this looks like it's something about focus

Or Window activity (which is related to focus). I'm wondering if one of my Qt patches is to blame.

yes, it seems to be caused by one of the patches. I'm trying to figure out which one...