@Alexxander@oliwor@jero
It seems its an issue of the saved vault of a old version, so i found a quite easy workaround.
Make sure your local vault has all passwords, disable(disconnect) the sync, delete/rename the files from enpass from the nextcloud and configure the sync again.
Enpass will create a new file, after that i no more have the problem.
Its quite ugly that we have to do that, but it seems enpass dont tested the updates quite good.