made a long program and it doesn't seem to work, BFS and OOP

the program is supposed to find the shortest path from S to E from a grid from my Input where the size is also my input, using the BFS method, the supposed Output is the reprinted grid with a traced path where the shortest path is here is the test case and expected output input: 15 15 ############### ##E.....####### #######......## #######......## ##......####### ##......####### #######......## #######......## ##......####### ##......####### #######......## #######......## ##......####### ##..........S## ############### expected output: ############### ##Exxxxx####### #######x.....## #######x.....## ##.....x####### ##.....x####### #######x.....## #######x.....## ##.....x####### ##.....x####### #######x.....## #######x.....## ##.....x####### ##.....xxxxxS## ###############