2014 Mac mini will only mirror 2nd display, not extend
I have a late 2014 Mac mini. 2.6 Ghz Dual Core i5. 8gb 1600 MHz DDR3. Graphics Intel Iris 1536 MB running on Monterey 12.0.1
My primary screen has been a sansui 30" that I connect by means of the HDMI to the Mac mini. I recently got an older Vizio 22"(it has an HDMI and VGA connection) and wanted to use it as a second display for extended screen.
Both screens work perfectly if plugged in individually. But if they are both plugged in it causes problem.
I have tried mini display to HDMI adapter into the Vizio. I also tried mini display straight to vga-no adapter into the Vizio. The result is the same. I switched screens and set the Vizio up with the HDMI and Sansui with the vga - same result. I have restarted the computer several times including 2 hard resets because the system preferences>display froze and wouldn't let me access anything else.
If I choose anything but mirroring the Vizio, the sansui will go blank and display the message "not supported".
It will treat the Vizio like it is an extended display, but the sansui screen will be blank. I have run my mouse to the right to find the Vizio screen with my mouse and can access the display drop down by that mean. But all the system preferences windows open in the now blank Sansui screen, which I cannot see to know what I am clicking.
Not sure what to add except all I want for Christmas is a new loaded M1 Mac mini. but since that's not likely, I appreciate any help I can get on this.
Mac mini, macOS 12.0