The story of TimeMachine is a tragedy: a revolutionary feature that made backups accessible for normal people allowed to lie fallow for a decade or more until it's as annoying and unreliable as anything else. I now use Carbon Copy Cloner to avoid the TM headaches.
I never found it to be overly reliable. It was reliable... for a while. Then would silently fail/stop working, or just tell you that it had stopped working and that whatever you had in it was no longer accessible.
And then I went to Acronis True Image backing up to my Synology NAS, but that became unreliable too - oftentimes when I'd go to do a restore, the client would crash trying to read the catalog.
So, like you... CCC nightly to my Synology, with a Snapshot rotation on it - snapshot the previous night's backup at 8pm, and then kick off that night's backup at 11pm.
Good nudge to look into using CCC. Which folders do you backup? It seems slower than TM so thinking of backing up home folder only