The front passenger tire locks up. When you put it in drive and let off the break it dosent start to roll you have to press the gas. It makes a metal on metal sound and then pops and frees itself

open the bleeder valve on the Rf caliper and push the caliper or pull to make the piston return into the caliper. Observe the fluid. Close the bleeder. is it rust ? or does the caliper seem stuck in place? Remove the caliper and inspect the hardware and linings as well as the rotor. Replace parts that are worn or uneven, compare to new. Use dielectric grease for lubricating the caliper slide hardware on reassembly. Do the same things to the other side as you did to the first side. If you found the caliper at fault, you can use remanufactured ones. If the rotors are too skinny to machine, you must replace them for safety. If this is beyond your technology, you can get it broke free and get a brake specialist to help. Most of them will inspect and diagnose for free. If some powertrain issue exists that is causing a bind, they can try to verify it , then recreate it while it is lifted up for inspection. you may have hub issues or drive axle or even the front diff. Using a process of elimination for finding the cause may be necessary, I cannot see it from here, so that's the best I have.

I did not mention the front bearings , the rotor should slide off the hub and the hub contains the front wheel bearings. If, when it breaks free, the operation is rough, or rumbles, attention to the hub showing rust or metallic dust around there could be at issue. Making it act up could mean sitting overnight, you can tell your tech that so he gets an idea of your concern and can recreate it or give it the correct attention.

To GL93 did you ever figure out what was wrong with your wheels or brakes please let me know I'm having the same issue on the passenger side front locking up but I know the driver side is locking up also , mine is only rear wheel drive same year make and model, (I thought it was the proportion valve but I haven't done anything lately to my truck)