Monitor not blanking despite screensaver settings

[Rich Shepard]

The new Acer SB-220Q monitor does not completely blank despite screensaver
settings.

The screensaver is set to 'Blank screen only' and to blank after 5 min and
cycle after 10 min. Power management is set to standby after 10 min, suspend
after 20 min, and turn off after 60 min. Instead, the screen is a pale light
and the bash shell login prompt is displayed.

I had this issue many years ago when I switched from CRT monitors to LED
monitors; I don't recall how I got the screen to totally blank to black, but
that's been the case ever since until I installed this new monitor
yesterday.

Advice needed.

TIA,

Rich