This is an official discussion thread linked from the www.privacytools.io website. This thread can be used for troubleshooting, questions, discussions and if you look for alternatives.
I really like SyncThing. It’s a flexible P2P sync option. I’ve used it both for syncing a large number of media files and syncing application config files (including on Android).
One thing to note is that they don’t have an iOS client. I was also not able to enable SSL for a remote client’s web dashboard even after trawling through multiple forums (SyncThing, Letsencrypt, reddit) for many hours. However, this could just be my lack of knowledge.