ID 604415 - Nuke can freeze when Viewing nodes if top-down mode is enabled on Rocky

Problem summary:
Nuke can freeze when Viewing nodes if top-down mode is enabled on Rocky
 
This problem seems to be Rocky/Linux specific, but the issue is not entirely consistent and has the potential to affect other operating systems as well.
 
Customer reported version:
Nuke 15.2v2
 
Customer reported platform:
Rocky 9
 
Steps to reproduce:
1) Download the attached topdown_issue.zip and extract the archive
2) Launch Nuke with the --topdown command line flag and navigate to File > Open Comp...
3) Select the included ~/topdown_issue/simplified_file_classic.nk file
4) Open the Script Editor window, and run the included ~/topdown_issue/freeze_nuke.py script
5) Note how the Script Editor never returns the "All nodes replayed" line, and observe Nuke's responsiveness while attempting to navigate around the UI
 
Optionally, repeat this process without including the --topdown command line flag, and note how the freeze_nuke.py script executes fully and Nuke remains responsive.
 
Expected behavior:
Having the render mode set to top-down should not negatively impact Nuke's performance and cause it to enter an unrecoverable state when Viewing nodes.
 
Actual behavior:
When Viewing nodes, Nuke can freeze and no longer function if top-down is selected as the render mode. While this occurs most consistently when using the attached Python and Nuke scripts, the same behavior has been reported when using other files and manually Viewing nodes in the Node Graph.

This problem occurs if the .nk file's render mode is set to top-down inside the Script, with the --topdown flag as it is in the above example, or when the NUKE_TOPDOWN environment variable has been set to 1 prior to launching Nuke.
 
On subsequent tests, Nuke's cache may need to be cleared in order for the problem to more easily occur (Cache > Clear All).
 
Workaround:
Besides only using the classic render mode, there is no known workaround at this time.
 
Reproduced by Support in:
Nuke 16.0v4 - Rocky 9
Nuke 16.0v1 - Rocky 9
 
Unable to reproduce bug in:
Nuke 16.0v4 - Windows 11, macOS 14 Sonoma
Nuke 16.0v1 - Windows 11, macOS 14 Sonoma
Nuke 15.2v2 - Rocky 9
Nuke 15.0v1 - Rocky 9
 
Earliest version tested:
Nuke 15.0v1 - This issue doesn't appear in this version, but a definite regression has not been identified due to the nature of the problem