You may want to check the pressure in all tires. A couple of times with different tire dealers I discovered they did not fill new or patched tires to the proper pressure.
I think they get used to filling tires at a certain pressure and don't pay attention when mounting higher load range tires. On my Load Range E tires with a maximum of 80 PSI they had them at 55 PSI.
Or
The new tires have weaker sidewalls than your previous tires. My last set of tires on the 5th wheel had too much flex in the sidewalls. When it came time for new tires I bought Michelin RIBS, very stiff sidewalls.
