I mean that fan speed change according to roll length not roll width, according to the heavy of roll 5 meter more heavy than 2 meter more resistance to pull need more speed fan to feed it. When sheet setup choosing piece mode that mean you set piece not length more than 1.6 meter so fan will be low when set edge or roll mode that mean you set sheet length more than 1.6 meter more heavy need more speed fan.
again I'm not sure test it.
check your fan that work or not from service menu (check fan).
another thing for good feed material check wheel the left and the right ,must have high edge and down edge , when set material the high edge must be out material the down edge must be inside.If the the wheel edge are level that mean you must replace , it's designed for pull material to right side and left side so material be level, you can test the wheel when remove it drop it on level table or ground must run in curve line not straight line too much run curve too much good less run curve not good need replaced.
if you have mid wheel it's always straight (level edge) not like right or left wheel .