That was the same issue I had with SyncThing, it just seemed to conk out at weird times and I gave up on it (for that purpose). It’s great for centralizing a directory of files from one machine to another but I didn’t love it for keeping a single file up-to-date with changes coming from more than one point on the network.
NP! It’s a great app, the dev updates it really frequently and I’ve never had any functional issue with it. I keep meaning to drop onto their git issues board and make a couple of small quality of life suggestions for the UI/UX as I use it dozens of times per day for work (there are some processes that currently take 5 clicks/per that could be reduced to 1 or 2 max) but that is a very small and nice problem to have.