I tested this on my own google sheets, and i think because everything in this line is Null that it just takes it out. (A bit annoying)
Although I couldn't find a way to configure the workbook to fix it.
If you put a space in column 1 on your google sheet It will keep rows as there is a value in the line now.
Sorry this is only a hack and not an out and out fix.
I attached a workflow for fixing up that data after the change in the data source.