A few years ago I set up KeepassXC using Syncthing temporarily to sync the database across all my devices. I fully expected to have to move to Nextcloud for database file management.

The KeepassXC / Syncthing combination has worked so well that I have no reason to change it. The databases are seamlessly synced across all devices (including my phone) without requiring any attention from me. Database issues due to multiple device use are almost nonexistent.

One note: For me Syncthing works much better with multiple devices using a star topology. When I initially set up a mesh configuration I had regular file sync issues. With a star topology they are very rare.