Footprint moves when 'Display' value is updated to 'Unchanged'

[ntwrknrd]

Steps to reproduce:

1. Open Rectangle Pro preferences
2. Go to "Custom Size & Position" pane
3. Create a new shortcut, using window dimensions from Display 2 (there are only two windows to choose from: Safari & Rectangle Pro - Safari is selected)
4. Click view footprint - the footprint appears correct.
5. Change the 'Display' value from "2" to "Unchanged"
6. Click view footprint - the footprint is much further north.

Additional details:

I'm using an Apple Studio Display vertically - not sure if that's a supported use case or not? Because of this, the dimensions in this scenario for the footprint were:

X 10, Y 409 W 1419, H 2058

Thanks in advance! -Chris