2014 Eco Diesel Brake and Accelerator No No

I have a couple intersections where I travel that I must cross right moving traffic to get in the left lane traffic on a very busy 4 lane 40 mph city road. I have always done it safely but I do like to lightly keep one foot on the accelerator and the other on the brake. This can cause the Ram to stall or lose rpm and I've had to coast into the far left lane.
This is something in the computer that I do not believe should be there. I took it in to have the problem checked out and they told me to keep my foot off the accelerator when stopped on the brake. I have never had a problem like this with any other vehicle ever. Not that I do it like that, nor would I but you certainly could not drag race my 2014 Ram 1500 Laramie Diesel.