Steps to reproduce:
Edit existing dataset, previously encrypted with a key, using ⋮ menu, Encryption options.
Enter two different passphrases
Different passphrases accepted!
Further investigation as following:
Lock the dataset,
Unlock it with a first entered Passphrase - works
Lock dataset again
Unlock it with a second (in Confirm passphrase) entered passphrase - fails
See attached screenshots.
This can be a UI issue, but I would validate backend APIs in case the UI calls them, to localize the issue.
Perhaps you can fix it by U1 release... which is in 2 days.