You didn’t note the ply or load rating of the tires. It seems you have mismatched tires. Depending on the weight of your trailer gives you tire inflation pressures. Pressures listed on the tires are max load pressures and those pressures depend on load rating. I would highly recommend matching all the tires, trying to guess pressures for two different sets of tires would not be something I would do! Over inflation and under inflation are the two biggest causes of blowouts!
Also whoever sold or mounted your tires should have known better or intended to just get you to where you were going.