I am experiencing the same issue described in this older post. What happens is:
Enpass goes idle.
I unlock it in the Chrome browser extension.
It waits for a little while, and tells me that Enpass is empty.
If I check the Enpass desktop app for MacOS, it also says it's empty.
I can fix this temporarily but closing Enpass, and reopening it. However, this is annoying. I've had to do this twice this morning already, and many times over the past week.