ID 153524 - GridWarp - Destination grid doesn't get initialized properly

Problem summary
When manually setting the Destination Transforms within a Grid node, restarting Nuke will not recognise the destination transforms and will use the source transform instead.

This causes issues as the grid warp will be off after each restart.
Toggling the source transform on/off will resolve the issue for the session.

Customer reported version
nuke.11.3v4

Customer reported platform
windows10

Steps to reproduce

1) Open Nuke

2) Create a Checkerboard and a Gridwarp node 

3) Use the Draw Boundary tool to draw a small box at the top of the Viewer window.

4) Within the Gridwarp Transform tab, untick 'use source transform' and set the translate.y to "-500"
    The grid should appear lower within the Viewer window.

5) Within the Gridwarp3 tab, set background to 'on black'

6) Save the script and close the comp.

7) Reopen the comp

Result: The Gridwarped Checkerboard will be at the top of the Viewer, when it should be at the bottom.

8) Within the Gridwarp Transform tab, toggle the Source Transform checkbox.

Result 2: The Gridwarped Checkerbox should be in the correct location.

Expected behaviour
The Gridwarp should keep the transforms after saving/reopening Nuke.

Actual behaviour
The Gridwarp will not use the chosen destination to transform values on startup.

Workaround
Using a Transform node after the Gridwarp will move the nodes information and keep it on restart.

Keep Source Transform checked, and add the settings to the Transform node.

Reproduced by support

This bug has been reproduced in:
Nuke11.3v4- Windows 7 - Mac10.14 - CentOS7
Nuke11.3v1- Windows 7 - Mac10.14 - CentOS7
Nuke11.2v1 - Windows 7
Nuke11.1v1 - Windows 7
Nuke11.0v1 - Windows 7
Nuke10.5v1 - Windows 7
Nuke10.0v1 - Windows 7
Nuke9.0v1 - Windows 7
Nuke8.0v1 - Windows 7 - Mac10.14 - CentOS7

Earliest version tested
- This issue appears to be in all versions of the product