Scheduling doesn’t work at all

Trying this plugin out and no matter what I do it doesn’t save my scheduled time. I can’t submit it after I schedule a timesince the “Submit” button greys out. And when I click “Update Revision” it erases the time I scheduled and shows the default “Publish on approval”.

Mind you I only have this plugin and the Classic Editor plugin active while testing this.

See video:

https://www.dropbox.com/scl/fi/d727qors3bhyptxne7qpb/chrome_CJPAN6e7oV.mp4?rlkey=bhp0tvgelv9k5egoapjg1kd23&dl=0

Certainly this can’t be normal behavior?