Syncthing-Fork, the primary Android app for Syncthing, isn't exactly reliable anymore. TLDR a new completely unknown dev has taken over maintenance and doesn't communicate well; it's probably not reliable without checking if someone has recently audited the source code.

https://forum.syncthing.net/t/does-anyone-know-why-syncthing...

That's unfortunate; thanks for letting us know. I only recently moved to Syncthing-Fork after giving up on the other Syncthing version I'd used for years, which seemed to do anything except actually sync on Android.