There is a possible fix. Open "cfm56_n1.obj"
Try to change all line u find and change:
from
ANIM_hide 0 [some number] sim/flightmodel/engine/ENGN_N1_[0]
to
ANIM_hide -1 [some number] sim/flightmodel/engine/ENGN_N1_[0]
Same with the right one:
from
ANIM_hide 0 [some number] sim/flightmodel/engine/ENGN_N1_[1]
to
ANIM_hide -1 [some number] sim/flightmodel/engine/ENGN_N1_[1]
Put -1 or less.
Seems work for me