Why is model is interacting with the surroundings causing it to glitch?

So, I have a character model with a play animation script inside of it to play a certain animation I have made, however, this animation is of them resting on a couch. If the couch has CanCollide set to true, the character just floats in mid air, however, when I turn the CanCollide to false on the couch, it all works perfectly and the model is in the right position. Is there a way I can still make the couch solid and I can't walk through it, whilst fixing this issue?