Chin not responding to the animations!

when I upload my model to Mixamo, everything moves just fine except for the chin of my character, I don't see any problem with it, and I don't know why Mixamo decides to leave the chin hanging as if it was broken or wasn't even there, please, help me, my work is due in 7 hours and I don't know what to do.

I have attached the photo showing what I mean, please I need help as soon as possible, thanks