I keep my KeePass database in my Dropbox, behind 2FA, with the main Dropbox password being a random string stored within the KeePass database. I have KeePass itself stored on my Dropbox as well, so I don't even need to install it to other Windows PCs, simply run the program. And the KeePass2Android app works quite well with this configuration.
Sometimes I get conflict files in the Dropbox folder. Not often, but a few times over the last year.
On iOS I have to open Dropbox and re-export the database file to see new entries. If I ever want to add or change an entry on mobile I have to manually export the file back into Dropbox. If the database in the app wasn't up-to-date, that will loose any entries added on desktop.
The KeeFox extension for Firefox works but is unreliable, especially on Linux.
Under File Input/Output Connections, check the box labelled:
- Do not ask whether to synchronize or overwrite; force synchronization
It's a program option, rather than a database one, so you need to set it on each computer running KeePass.
Dropbox stores the files locally (on the phone, the kdbx file is marked to be cached and updated offline and I use dropsync)
If someone deletes my kdbx file from my Dropbox account, and I don't realize this in time (before all my devices sync _and_ my backups run out, so very small chance given the nature of the file) I'm in a lot of trouble...