We had friends that bought a brand new high end 5th wheel and had the cheap tires fail. The manufacturer replaced them with another brand that soon failed (heavy trailer). I kept telling him to put on truck tires. After the second failure he finally put on Michellin LT truck tires and things have been great for over five years.
When I had my boat that weighed in at 5K, the first thing I did was toss the ST tires and put on passenger car radials. I never had an issue. When it comes to heavier trailers, dump the ST tires and go with LT truck tires that meet the load rating. You'll be happy you did.
Don & Mary
2014 Newmar Dutch Star - All Electric - 450 ISL
2016 GMC Canyon 4WD Crew Cab