X11 resumed imonitor stays black after lasting suspend

[CaptainBlood]

Plz note HDMI to VGA adapter here.

It's been a while here, about a month that when waking up, screen enlights then flips back to back screen.

The only way to get control back is to:
switch off monitor.
switch on monitor.
quickly switch to tty, e.g. Alt+Ctrl+1
quickly strike any keys at login prompt, Ret included.

At this step monitor may turn black again. If so repeat the sequence.

If monitor remains visible, do the Alt+Ctrl+X sequence to switch back to desktop session.

It is likely to happen if monitor went in suspend mode long enough.

Any idea what is happening, or how to fix?

Thks 4 ur attention, interest & support.
_________________
USE="-* ..." in /etc/portage/make.conf here, i.e. a countermeasure to portage implicit braces, belt & diaper paradigm
LT: "I've been doing a passable imitation of the Fontana di Trevi, except my medium is mucus. Sooo much mucus. "