I use syncthing to sync my KeePass database. I have a small VPS that I can sync to for when wifi is weird/as a backup, and Syncthing can do E2EE sync to a remote device, which is what I'm using. So all the files on the VPS are encrypted, but my phone or my computer can pull and push to the VPS.
Technically, you don't even need a public endpoint, devices on the same network should be able to find eachother, and even over the internet devices should be able to find eachother through Syncthing's e2ee public relay servers. However, in my experience syncthing over the internet has been unreliable, so I use a VPS.