Issue with popout gauges (B737)

hi all

have used the forum anonymously many many times over the years to solve a plethora of issues but this one has me so stumped that I need to ask.

have recently changed PCs after my old one had a meltdown. Still playing FSX (SE) though despite the new hardware….everything works absolutely fine with the software including all the aircraft I have always been using, except for one major problem and wondered if anyone can help:

I use pop-out gauges on a variety of 737 models, moving the PFD and MFD to a second monitor, the FMC to a third which is a touchscreen monitor.
Graphics card is a Geforce 3050.

Setup is therefore as follows:
Monitor 1: 737 Virtual Cockpit (connected via DP)
Monitor 2: PFD / MFD (connected via HDMI)
Monitor 3: FMC / ATC and others (connected via DVI)

FMC / ATC on monitor 3 work fine, reacts to touch inputs etc and refreshes correctly, but the PFD / MFD freeze once moved to monitor 2. As soon as I start to pick up speed, the PFD should show speed increasing on the gauge but it remains frozen at 0 knots (the actual gauge on the main monitor shows the correct, increasing speed). Turning e.g. Flight Director on and off also shows up in the VC but not in the PFD on monitor 2. Similarly, inputs into the MCP such as CRS changes show up in the MFD in the VC but the MFD on monitor 2 remains frozen. 

I have tried everything in the settings of the game, the NVIDIA settings for my graphics card, even reinstalling gauges etc but nothing works. Its making me tear my hair out and to be honest, I dont have much hair left to lose...

Does anyone have an idea as where else to look or anyone had a similar issue with frozen pop-out gauges?
Thanks in advance!