Well Bobpie,
You are now witnessing what many, many of us have already gone through. JUNK MICHELIN TIRES!!!!!!! And, with a bit of searching on this and a couple of other RV forums, you'll find lots of folks that have ventured over to quite a few other brands. Not only for better dependability but, for quite a bit less money too. We did it about 1.5 years ago when the 6 year old, protected just as good as yours are, 40K mileage 255 80R 22.5 Michelin XRVs were cracking. Those were and are, proprietary to Michelin so, I found some 265 75 22.5" Yokohama RY-103 LRG tires for about $2,000 less for all six than the junk Michlens.
Way better price, ride is fantastic, the coach handles outstanding and, we're waaaaaaay better off in the pocket book.
Scott