Steps to reproduce:

1. Open a new shader graph
2. Setup a simple graph (world position -> swizzle node -> output node 'color')
3. Set swizzle node input mask to 'xyz'. Can visibly see the mask input change to vec3
4. Set swizzle node input mask to 'xy'. Can visibly see the mask input change to vec2
5. Undo (crtl/cmd+z). Can see everything move back from vec2 to vec3
6. Click on the input mask field
7. Click off input mask field.

Actual results: Input mask stays the same but notice the actual visual output changes, and appears to become a float perhaps?

Expected results:  The mask and visual output remain consistent as vec2, the result of the undo operation.

Reproducible with versions: 6000.5.0a7, 6000.3.5f1

Tested on (OS): MacOSX Tahoe (MacEditor ARM M1 Max)