Just adding I think this is my issue too, not sure if there is anything I can provide besides it’s a Samsung 24 ultra (using the f-droid syncthing fork). It will do massive amounts of transferring for a few seconds and then dies for many minutes, and does it all over again. It actually reads very much like this thread: DCIM/Camera won't sync - #9 by cwilmot except it’s not exclusive to DCIM (not sure if that person tried other stuff, I did- in general it’ll go firehose mode and then not). Logs don’t appear to be reporting any errors. Folders are stuck syncing, with no transfer going on, the remote devices section of the webui says it’s up to date.