Same on MacOS Monterey with AppStore version. This issue exists for a long time. I never reported it.
How to produce:
Once MacOS has been woke up from sleep (needs to be a longer time, e.g. over night) and Enpass App Icon on Safari has been clicked it asks for the PIN. After entering the PIN, Enpass crashes.
Please find the stack trace attached. txt files are not allowed. Hence, I renamed it to plist.
enpass_monterey_stacktrace.txt.plist