Yes, it is half model, me too I've added a symmetry region in the model block (lateral face of both the splints not only the lower one as you did), I've noticed that if I open the mechanical model block there is the symmetry region, but if I open the static structural block the symmetry is not considered. However, I've moved on the CAD only the two splints to be in contact and they are since the contact results closed. But all the other six contacts are near open because I didn't moved them since you said that friction can be suitable too.