there is not a trailer tire made that is immune, not even the goodyears that were supposed to be the greatest
trailer tires are made differently than car tires, and they will separate like that especially as they get aged out.
tire pressure has a lot to do with it too
the type of tire
the plies
usage.
even air flow characteristics
Trailer tires are rated to run at or close to 100% load all the time. So if the tires are rated for a maximum of 1760 lbs (each tire), they work best running at 1700+ lbs on each tire (this includes the trailer's weight, the axle's weight, plus any cargo weight). Putting E F G rated tires on a trailer that carries 1000 lbs isn't solving any problems, could create many though.
We used to tow about 8500-9500 mi a month during the summer, pulling 24' enclosed with the race car in it. Blowouts were common. Started going from D rated to E and it got even more common. Year or so later we decided to put the D rated tires back on and while we were replacing stuff, I had them put a TPMS on the trailer that links up to a monitor in the dash. Nowadays I think you can get them with bluetooth so the phone can display it through an app (or iPad, whatever...) So we would leave the track at 1200 hr, TPMS said 65 psi. 150 mi later they were closing in on 80 psi! There is a lot that causes that kind of heat, and a lot goes into dissipating the heat too. Airflow is a big deal. Steel wheels hold heat, aluminum dissipates it a lot faster. That sorta thing. I started using nitrogen and that helped quite a bit but we still had to stay on top of them. D rated tires were less likely to grenade than the E's were. The trailer guys at one of the tracks explained why, has to do with physics. Most folks think that the more plies the better but the more plies also means the carcass is much thicker and heavier and that all holds a lot of heat, gives a lot less which is hard on suspension and chassis (that is a big deal hauling higher end race cars), etc etc. Before I sold everyting off we put 16" wheels on it with 16" LT rated truck tires. Those worked GOOD. Never had one of them blow, they always kept pressures in check too, and trailer rode excellent. Tread lasted a lot longer too. I sold it with those on it and now I'm out of the race car business.