There may have been an equipment swap. The OP only said it was still a 737 and the GA said there was an equipment swap. 737 layouts differ and the exit rows can be rows can be 9, 10 or 11 depending which might have caused the problem.

Most likely the OP moved to a 735 where row 10 is in E- and the exit is row 9. The OP previously might have been in a 733 or 735 ex-SHT where 10A is the exit with no seat in front.