If it has 16” wheels you can find good LT tires, but also good heavy ST tires.
If it’s 15” or smaller wheels, STs are your best option. Buy the heaviest rated ones you can in the proper size.
Someone will invariably post about 15” or smaller LT tires but there are not any made that are load Rated as high is good trailer tires
Also note, sometimes trailer tire issues are the tires fault as in cheap or old tires. Other times it’s inflation or lack thereof or tire damage.
In your case, sounds like cheap tires were the issue if you know they were properly inflated.