maybe you need to file the rakers.
Folks up the road wanted a load of fresh cut green wood " to hold a fire over night" their chimney was so clogged the soot slayer shook loose...
check the coil and flywheel if there is no spark , mine was coated with baked on sawdust . sanded it up and it starts like a new machine. mine is...
I wonder if Hardy board would work , it's cement board with a fire rating ? and it's very affordable compared to factory replacement board.