Opening Home Assistant Settings could discover a Supervisor update and then block Home Assistant, operating-system and app updates until the next daily task installed it. Supervisor starts its automatic update whenever its version information refreshes while the system is running, closing that waiting period.
Paulus Schoutsen also makes a manual update request share an automatic update already in progress, avoiding a competing-job error. A backup restore that needs a newer Supervisor distinguishes an update under way from one that cannot start automatically.