Urgent help blue tit chick stuck

i have camera in my blue tit box, chick which is not ready to fledge yet, seems to have its foot caught, both parents still feeding it. I’m worried if it moves so much it will wear itself out or hurt it’s legs. If it was not attached, it would fall out the hole in the box! As it keeps trying to do that. Would parents have tethered it?  It seems like nesting material is wrapped round it’s legs.

what shall I do?