ID 472814 - Trying to use PSD Breakout Layers in Nuke 13 breaks the undo stack

Problem summary
Trying to use PSD Breakout Layers in Nuke 13 breaks the undo stack.

Pressing Ctrl+z/Cmd+z will undo multiple actions, which were taken after pressing the Breakout Layers button.

Customer reported version
Nuke 13.0v1

Customer reported platform

macOS 11.2 (Big Sur)

Steps to reproduce

1) Open Nuke.

2) Create a Read node and read in a PSD file.

3) Click the Breakout Layers button on the Read node. This will only create a Backdrop node, due to the following known issue:

ID 471335 - PSD Breakout Layers do not work

4) Close the current comp (File > Close Comp...).

5) Create a number of nodes in the Node Graph. For example, press the G key multiple times in the node graph to create a number of Grade nodes.

6) Press Ctrl+z/Cmd+z to undo. Notice that all of the created nodes are removed with one undo.

Expected behaviour
Pressing Ctrl+z/Cmd+z should only undo one action at a time.

Actual behaviour
Pressing Ctrl+z/Cmd+z will undo multiple actions, which were taken after pressing the Breakout Layers button.

Workaround
The undo stack should work correctly after closing and reopening the current Nuke session.

Reproduced by support

This bug has been reproduced in:
Nuke 13.0v1 - Windows 10 - macOS 10.15 (Catalina) - Linux CentOS 7 - Regression

Unable to reproduce bug in:
Nuke 12.2v6 - Windows 10 - macOS 10.15 (Catalina) - Linux CentOS 7

Earliest version tested
Nuke 12.2v6
- This issue doesn't appear in this version and has regressed