amd firepro w4300 multi-screen issues

[steve76063]

My workstation came with an AMD FirePro W4300 card with 4 mini-DisplayPorts...  I've tried to connect 4 monitors, and have had nothing but headaches :(.  These are the monitors:

24" Gateway HDMI monitor

22" Gateway HDMI monitor

30" Sony HD TV/Monitor (connects with VGA)

18" TruTech HD TV/Monitor (connects with VGA)

For all monitors, I use a mini-DP to DP cable, and then a DP to HDMI or VGA cable to get to the monitors.

What I'm seeing:

With the TruTech TV/Monitor connected, I'd sometimes randomly get (and usually get when the system powers up the monitors after they've been shut-down due to the power scheme) the monitors would all flash on and off, and I'd hear the device detach/attach sound from the system.  This would usually go on for 1-10 minutes!  When it finally settled down, my icons which are normally on the far right screen (the 24" Gateway monitor) would be rearranged and on some other monitor (usually the 22" Gateway or the 30" Sony).

So, I removed the TruTech from my system - now down to 3 monitors.

With this setup, I no longer had the flashing, but 8/10 times that the monitors would power up after having been shut down due to the power-saving scheme, the icons that should be on the far right screen would appear on one of the other monitors as they're powering up!  After all the monitors finished powering up, the icons would usually end up back on the far right screen, but rearranged because of the different resolution on the other screen(s).  Also, if I had any window open and placed on the left or middle screen, after waking-up, the windows would all be moved to the far right screen!

I've then removed the Sony TV/Monitor (now down to 2 monitors), and the symptoms still occur!

The ONLY way I've found to prevent the icons/windows from shifting around is to use only 1 monitor (which defeats the entire purpose of the new system  ).

The system this is replacing used an nVidia card and the same monitors, and had none of these issues (that system could dual-boot to Win7 or Win10, and I had no problem with either), so I'm suspecting the AMD card/driver.

Has anyone else had any similar experiences and/or found a fix for this?  I've been going back and forth with Hp Support, and they've suggested a number of things to try, but so far, none have helped.  Their latest suggestion was to try the nVidia card from my old system in the new one, but unfortunately that card doesn't support UEFI, so the system won't even boot up!