I tried Nextcloud a while back and was not impressed - I had issues withe the speed of the Windows sync that were determined to be "normal" with no roadmap to getting fixed. I'm now planning to move off Windows desktop so that won't be an issue - so I thought I'd try again.
I went to nextcloud.com, clicked on Download-> Nextcloud server -> All-in-one -> Docker image - Setup AIO. This took me to the github README at Docker section. I'm already running docker for other things so I read the instructions, setup a new filesystem for my data directory and ran the suggested docker command with an appropriate "--env NEXTCLOUD_DATADIR=". I'm then left with a terminal running docker in the foreground - not a great way to run a background server but ok, I've been around for a while and can figure out how to make it autostart in the background ongoing. So I move on to the next step - open my browser at the appropriate URL and I'm presented with a simple page asking me to "Log in using your Nextcloud AIO passphrase:". I don't have a Nextcloud AIO passphrase and nothing I've read so far has mentioned it. When I search for it I get some results on how to reset it, but not much help. I could probably figure that out too, but after reading some more I found that Nextcloud requires a public hostname and can't work with a local name or IP address. I'm already running my home LAN with OpenVPN and access it from anywhere as "local" - I don't really want to create a new path into my home network just for Nextcloud.
I'm sorry - I know this sounds like a disgruntled rant and I guess it is. I just want to check that I'm not missing obvious things before I give up again. All I want is a simple file sync setup like onedrive but without the microsoft.
Seafile. It's super fast and lightweight. There are some caveats though:
Data is stored in git-like chunks on the server side. There is Seafuse and Sea drive functions that you can leverage to "assemble" the data on server side for backups. I personally use rclone mount, then backup.
Paywall hiding some features. The community edition is free but is missing some features that pro has. Pro edition is free for 3 or less users.
Documentation isn't great. The forum is active so that's helpful, but some of the docs take some time to understand
Chinese owned. As far as I can tell, there is no call home for a self hosted server, so I don't think it's a worry in that case.
All that said, I like it much better than Syncthing for it's selective sync. All files on each client are synced to the server. But unlike Syncthing, it doesn't sync all data with each client. This is vital for me with some devices with small storage drives, so I would t want all files to sync. Yet I can still reach to the server from any client and pull data from any other client. Syncthing has an ignore flag, but that seemed way more trouble to setup than just sticking with Seafile.