I hope you are able to track this down.
In your case, the strange thing is that it was working for an hour or so and happened without any input on your part. Is it possible that either Resolume or TouchDesgner updated itself on start? That could have reset the NVIDIA profile settings?
The Windows Graphics Settings do take priority over driver settings as I mentioned earlier and I gave a link to NVIDIA advice in this post.
I expect that you have already made sure that both programs are not registered with Windows Graphics Settings and that both have a profile established with the NVIDIA Contral panel “Program Settings” and both “OpenGL rendering GPU” and “Power management mode” specify the NVIDIA GPU.
The only other thing that comes to mind is to remove the NVIDIA profiles for each program from the NVIDIA control panel, and set Windows Graphics Settings for both to high performance. Resolume will detect that the profile is missing so don’t update that for the duration of the test. For this reason, it probably isn’t a good permanent solution but the test might be worth the time.
Meanwhile NDI will work quite well on the local machine but it uses the CPU and compression methods that inevitably take some time.