Tire PSI newbie question

[Garfish]

2017 16' sport has Goodyear ST 215 R75 14s and says on tire max PSI 65. Owners manual says inflate to 50 and from the dealer it is 60, cold. If loaded about 3200 then what should PSI be?

[Boxite]

The label on the side of the tire is informing at what weight the tire will support it's maximum load. The owner's manual is making a recommendation based upon the mfr's knowledge of the trailer and it's capacity.
The tire pressure at which the dealer placed the tire could be the result of the dealer making an error, having a poorly-calibrated gauge, or deliberately overfilling the tire to avoid having to make daily checks (knowing that 60 psi will not damage the tire per the sidewall label.)

Follow the owners manual, IMO.