I think this is just a matter of formatting on the elements that are being used to visualize the data.

Looks like your repeating group on the right side has color for separator which causes all of the cells to appear as if they are there…remove that color

Screen Shot 2021-01-14 at 12.49.32 PM

Then put a group into the cell and put the formatting so the separator would be a border on the group…then put conditional on the group to not be visible when the current cell data is empty.