See online demo:
Steps to reproduce (seen in Chrome and Edge):
- Click the "x" on the 2nd to last record on page 1 to mark it for deletion (Click "OK" at the prompt)
- Click "Add new record" button
- the record marked for deletion moves up by one record (but fortunately it appears the correct record will actually get deleted upon Saving)
- a blank new record is creating correctly
If you repeat this procedure but choose a different record for deletion you can see it is functioning correctly.
I am seeing the same behaviour in my own project.