Row height does not go back to normal after clearing grouping

[pavish]

Description

• Group a table by a column, notice that the group headers are displayed.
• Remove the grouping.
• Notice that the rows in the place on the now-removed headers (i.e. with the same index) retain the height of the group instead of going back to normal row height.
• When group is applied:
  
• After group is removed:
  

[pavish]

This is a regression noticed after #3755.