Boot time scan - not working?

Hi
Avast Free. How should boot time scan behave and report? When I schedule a scan, it certainly triggers on reboot, but disappears off the screen almost immediately, and the report file (awsBoot.txt) doesn’t look right (see below). Is this normal behaviour, and if not, any suggestions as to how I make a boot time scan happen for real?
awsBoot.txt:

10/08/2020 08:42
Scan of C:

Scan of *STARTUP

(that’s all, just these 4 lines).

Hi
have a look here