multiple displays on Monterey 12.2

to get a Mac display to become active, you need the Mac to query the display, and the display to answer with its name and capabilities. Otherwise, the display will not be shown as present, and no data will be sent to the display. "No signal detected" is generated by the DISPLAY, not by the Mac.

This query is only sent at certain times:

• at startup

• at wake from sleep — so momentarily sleeping and waking your Mac may work

• at insertion of the Mac-end of the display-cable, provided everything on that cable is ready-to-go

• on invoking Option-(Detect Display) button in Displays preferences (from another display)

Note: Displays supported through Docks require that the dock get working and stable FIRST. This may take longer than a directly-connected display, so the initial query to the display may go un-answered. You may need to manually invoke the query again.

I'm having similar issues... I also have an older MBP 2019 i9 16" running Big Sur 11.6.3... I can plug in all 4 monitors and it works no problem, and has for years. However with my new MBP 2021 M1 16" running Monterey 12.2, I can only get any 2 at a time to work. If I have 2 connected and add a 3rd, then the 3rd either doesn't display, or it does and one of the first 2 goes dark. I've tried using hubs, direct connection, reboots, sleep/wake, detect displays, etc... basically it seems like Monterey 12.2 won't support more than two external monitors (at least for me). Either that or it's an M1 issue.

<< and 1 usb-c hub with a usb-c port for power and a hdmi port for my 4th external display. >>

what Make & Model Hub?

what make & model HDMI display?

what HDMI cable?