KWalletEditor::saveEntry() does not call setFolder.  This can result in the entry getting saved into the wrong folder.  For example, if chromium is connected to the wallet at the same time you are editing an entry in kwalletmanager, the entry can wind up getting saved into chromium's folder instead of the folder you have selected in kwalletmanager.  Then the next time you open kwalletmanager, the changes you made to the entry are apparently gone (really they are still there but in the wrong folder). I'm using kwalletmanager version 16.08.3 from debian stable, but from looking at your git repo, this bug still exists in the current version of kdewalletmanager.