I've had all manner of issues, backing up via Ethernet and Wifi to FreeNAS and then to Synology. The only backups with Time Machine I had no issue with were to local USB drives.

Time Machine would work and work and work until one day... "Cannot write to your backup" and the whole thing would be corrupt and not even readable.

Flirted with Acronis TrueImage which was worse. Hell, even before catastrophic corruption, attempting to restore a file from a decent size catalog even over 10gbE would generally cause a beachball for minutes and then you had to be very careful to browse exactly to the location and file you wanted to restore (poking around trying to find it would inevitably totally crash the client, and even being careful sometimes would).

I ended up moving to Carbon Copy Cloner to Synology, with the Synology taking a snapshot 10 minutes before CCC starts its nightly run.

A few months in and it has been rock solid. If I want to restore I can just browse the snapshot in Synology and either copy a file directly from the Snapshot browser or mount the entire snapshot as a shared folder.