Adobe Reader DC

Hello.

We had a problem in our company lately with signing pdf documents with electronic signature.

When an employee tried to sign the document, the card with signature ID didn't pop up until they closed the file. Once they signed it like that, the signature was wrong. It happens to some every few weeks or months, and to some it happens every 2 days or so. The process that the signing should have would be to sign -> save file as -> enter security number for the certificate card -> positive signature on saved file. Instead it is "signing -> save file as -> app either crashes or you have to close it manually as it is unresponsive -> certificate card pop up for security number -> signature failed on the saved file.

Uninstalling and installing the app again (we're installing the 2019 version as 2021 version sometimes doesn't work with signatures) solves the problem temporarily. It happens all over again the next day or 2 days later.

We tried disabling updates for Adobe Reader in registry and 2 other places but it was also somewhat temporal fix as next week it happened again.

We're totally lost to why it happens so often to some people and to others from time to time and we have no idea how to solve this issue.

What may be causing the signature fails?

OS: on the computers that have the problem it's Windows 10 Pro

Adobe Reader DC version is "Reader DC 2019.008.20071 Polish for Windows"

Kind regards, Paul