What is the maximum tire pressure recommended for that tire?? It's listed on the sidewall. 46psi seems too high and they may be overinflated. Tire size shouldn't have any bearing on the TPMS...just the tire pressure. I think that 46psi would bang the hell out of your suspension and steering mechanicals.
Did the TPMS light go out after the dealer upped the pressure?? If so, then drop the pressure a couple of pounds at a time and drive for 15 or 20 minutes or so, and keep doing this till the light comes back on. Then give the tires a pound or two more air.