I had this happen recently also, it felt like the breakaway switch was holding the truck back. We traded for this new 5er in Ohio, drove it around for 3 weeks in Ohio and Indiana, revisited the dealer to have a noisy fan motor replaced. We drove aprox 1500 miles without a problem, got off the Interstate 15 miles from home in Florida, and at the first light we stopped at we had a problem accelerating as the op stated. The truck really worked getting up to 30 or 35 mph and it would release and truck transmission would slam to catch up, continued to happen all the way to the house,got to my driveway, backed in and did not happen jockeying the trailer around. Hooked up and towed it to have the hubs pulled, all was fine, I replaced the E. disconnect switch and am hoping for the best. This the same brake controller that I haved used for the last 5 yrs (prodigy p2) and the same truck in my signature for the last 15 yr, need to update the 5er in signature. I have never seen this problem discussed.
