Hi,
There is a bug in the interactive grid with adding and deleting rows to an empty grid without saving. Steps below are without 'Add row if empty' . enabled.
Tested on latest Apex version.
Add record to empty IG. Don't save.
Delete record.
Add record.
Steps are slightly different with 'Add row if empty' enabled. (one more delete record step)
Bug seems related to the IG cell selection. Leaving edit mode with escape before deleting the record prevents the bug from happening.
Regards.