Time Machine backups are but one of 70-80 background services which are run by macOS dispatching systems. Here’s a list of some of the others.
If there’s one update that we need, it is an App Store app which works reliably. The current one suffers from general dystopia.
Installing a Combo update of OS X is a popular panacea for puzzling problems. But you need to do a bit more to complete the job.