P: Select Subject mask is shifted by Generative Expand

To recreate bug:

Part one: normal editing.

Edit a photo in LR.

Edit in Photoshop, using layers, adjustment layers etc. 

Save / close

Go back to LR.

Part two: further edits.

Edit PSD photo more in lightroom using select Subject Mask / Select Background mask.

'Edit in Photoshop'

Generative expand background.

Save / close. Return to LR and find this:

Once this happens AI masking can't be used with the image. its consistently masks the image incorrectly, and the only way to resolve this is to delete the image and start over again.