System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 1070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 456.38

Blender Version
Broken: version: 2.92.0 Alpha, branch: master, commit date: 2020-11-30 18:56, hash: rB007a0e43a01a
Worked: (newest version of Blender that worked as expected)

adding a new frame around existing frames in the node editor results in the nodes which were in the original frames being moved out of those frames into limbo

1. Create material in shader editor
2. drop down a few nodes (any)
3. select them and press shift p (make sure node wranger is enabled for this shortcut to work)
4. The nodes are now inside the frame, move the frame to test and the nodes will move with the frame
5. now box select the nodes and the frame
6. press shift p again to create a new frame around those
7. all relationships are now lost between the nodes and the original frame (test by moving one of the original nodes and you will notice you can move them outside of the original frame (instead of the original frame expanding as it would if the node was still a child of the original frame.)