I used to use Vaultwarden (a fork of Bitwarden's open source, self-hosted password manager - I do recommend it!) but decided to use Proton's solution since I have moved over to their ecosystem for everything else. I've used LastPass years ago and the comparison to Proton Pass isn't even fair; Proton really has nailed the UI, experience, and details of Pass. Unless LastPass has really changed things, their system is a combination of their old interface and new interface with some features seemingly half-complete. Plus they've lost my trust. Proton on the other hand seems to have a much better architecture for the security of accounts as well as extra layers of safe-guards that can be added if desired.

I highly recommend Proton Pass to everyone!

unable to understand how it works, sometimes appears when making a new sign in sometimes don't

Simple and sleek. How every app should be