Right now, I have Enpass on two different Windows devices (and an Android device but let's leave that out for the moment). The keystore is backed up to Box automagically.
Starting condition is that devices and keystore have the same Master Password. On device A, I change the Master Password, which changes it for the local A device and for the synced backup. On device B, I cannot sync unless I give the NEW sync Master Password (from A). However, once it is synced, the Master Password of the device B is still the old password from before. This is totally unintuitive and MUST be changed. If you went through the trouble of updating the Master Password on device B to sync the keystore, it should AUTOMATICALLY change the device's Master Password. But currently it does not. I have to go into settings and once again change the Master Password on device B (which again changes it for the synced backup (but this time the password is the same as it was before (new A password) so you don't have to go through this cycle one more time on device A)).
It's all a terrible mess. And add a mobile device into this and it's again even worse because all that I just said applies. You have to put the new password in to sync, and then you have to manually change the local password to match the new sync password you already entered.
Terrible terrible user experience and NOT intuitive at all.