Hey gang,
First time, long time.

I run a pro AV and streaming business and I've been helping a church on sundays with a strange Vmix problem.
They are having their entire Vmix window/session dissapear/close randomly without notice. Externals, streams and records are stopped. The process generates no crash logs or documentation. The process appears to be functioning normally in task manager, but the window disappears from the taskbar. Restarting vmix will open the project back but any cameras connected via Decklink Duo 2 remain offline. The problem gets stranger in that I brought in a second vmix machine with different hardware and when plugged into their network started to see the same behaviour. The second machine has never exhibited any crashing or closing behavior in its life.

Specs are:
MACHINE 01 (Original church PC)
-Intel i7-9700KF
-16gb RAM
-GTX 1650 Super
-Vmix 24.0.0.62
-Windows build 19041.1052

MACHINE 02 (My professional Vmix rig)
-Intel i7-7820X
-32gb RAM
-GTX 1080
-Vmix 24.0.0.49
-Windows build 18362.900

Church PC runs 3 decklink lines in, 4x GT titles, 2x videos, 1x dante RX via DVS, 1x NDI input generated from Pro presenter (just words with alpha)
My PC ran the same setup except no dante RX.

The puzzling thing is that the problem is not recreatable on demand. Sometimes it will run for a few weeks without issue, but today it "closed"
3 or 4 times. Church AV tech has installed windows on a separate disk and done a clean vmix reinstall also with no improvement.

Scouring the forums, some people think it is NDI, however Martin replied in a forum earlier this year saying that is unlikely and that the window dissapearing is a GPU problem, however this seems strange as we have seen the behaviour displayed on two different PCs with different GPUs (although admittedly both Nvidia cards). However we did see a brief 100% spike in the GPU performance manager in windows around the time of the crash.

Currently running a test with Church machine running NDI input and My PC not, will report back findings.
Any assistance or reccomendations you have would be very welcome.
Thankyou!