<<<<You mean the problem occured during pause FSX (simulation stopped)? This means the problem have to be outside of FSX.>>>
Yes; correct.

>>>On your screens I can see that you have subdivide the 2D panels outside the FSX-Mainwindow. <<<<
If possible at the different aircraft I use 2D-panels and transfer other panel windows to the second window to have a better look on the switches as using virtuel window.

But I suggest a reproducibility test.
After fresh PC start and cessna cold&dark I load c-130 with subdivide 2 d windows. Situation as before with simulation stop about 1 hour.
After that the same procedure but without subdividing.

One question, do you using virtual window?