No inconvenience at all, just reporting... and even not a fault of EnPass...
Issue seen on:
OS: Android 9 With Feb updates (OxygenOS 9.0.11
EnPass: latest avaible on play store 6.4.2.327
Google Keyboard: Lastest that I know of as with google it's hard to know what is "Latest". Should be 9.2.7.303045247
As I can tell it's all about a feature of gboard that could be usefull but can be an issue when dealing with password....
The feature can be enabled/disabled in gboard. Don't know the extent of the issue. As I know in android apps can't access clipboard while in background. Don't know about this gboard feature of advanced clipboard... I mean I don't know if the content inside can be read from other apps or can be used only inside gboard itself. I would say that's a minor issue if only gboard can access that special clipboard as there's still possibility that someone could take possession of device and take a peek (manually).
As I can see it, this is inevitable (for now) but can be mitigated by disabling "adavanced clipboard" in Gboard.
Some scrrens to clarify....
In this screen I had already created something just for test in EnPass with a random password... On EnPass I had done a tap on password, selected Copy and then as you see in screen I copied it... All fine as expected. Then waited 30 seconds or more.
Then again I used the "paste" command (long press on entry field and then select Paste).... But as expected nothing happens as EnPass change clipboard to nothing as expected and mitigate possibility to paste password long after they are supposed to be used.
Now the trick.... when keyboard is out, tap on "clipboard" incon on top of K-Y keys
A screen of what gboard shows....
Will appear an history of everything pasted in last hour, including password... So you can tap on it to paste and/or read it