If the door frame is deformed due to collision, it can be reshaped with a flat screwdriver or pliers, but it should not affect the expansion and contraction of the curtain.

If the curtains are dented, in this case, it is best to replace them with new ones.

Generally, the curtain on the shutter door is stuck in the guide groove or deformed, which can be repaired at the notch where the shutter door enters the guide groove.