I am fairly new to Syncthing but have it running now on Windows, Linux, and Android. It does a fine job and I’m happy with what it does. It is the Android client at issue for me. This is the -fork version I got from the Play Store. It does not start when the phone starts. That pretty much defeats its function for me and I have to manually start it after which it runs fine.
I am told that Google/Android 17 are very aggressive protecting battery life and that autostart is difficult on that platform. I don’t see a way to get it to autostart so I wondered if it could be enabled in the app itself to do that.