My backup is currently stuck on /var/lib/systemd/catalog/database
It also says 17760 files (-4000281 bytes) to go
Is there an issue or is it a case of waiting it out?
Please describe how you see that. If on a progress bar, look at the position and percent too.
Having given it some more hours, did anything move? Check About → Show log → Live too.
Profiling is very sensitive (lots of output too). Can you see system resources are being used?
Sometimes it’s hard to distinguish between slow due to system limits, versus not trying uses.
An overworked system might, for example, be slow to fill out web pages. I think you had that.
Further analysis might need a log file to more thoroughly look at the history that came to this.