Hi, was having the same issue, where Nodes kept getting hidden behind the video preview window.
The solution, at least in 12.5 is to right click on the node field and choose the "cleanup node graph" which does the trick well. Alternatively, switch from arrow to hand mode which allows you to slide the entire node field around (so you don't have to resize windows to get access to hidden nodes).
What I don't understand is why the software doesn't keep a perfectly clean node field that gets captured in a still frame can't remain a perfectly clean node field when it gets applied. So it goes.