The need to use a third party plugin to get any form of cloud sync working for one. Minor weirdness with it scrolling through your secret share structure on the left instead of up and down your passwords if you have accidentally clicked over (a feature that acts more like a bug). The lack of ability (or at least any documentation) on how to use something like Google Authenticator as MFA for the database.
The external sync is a feature for me, not a bug. I can use whatever tool I want to sync between my devices (I use Syncthing) and do not need to trust some company with storing my stuff on their servers and not fiddling with them.