Love this app (and its iOS version)! There is a bug in latest version (4.6.1). Open the app and unlock it with your mater password. Afterwords from time to time when you bing up the app again, it won’t accept any input for your mater password to unlock it. From that point on, you have to quit it before you can unlock it.
Thanks for the attention.
Alex1668 about Enpass - Password Manager