Hi Guys -

I have a 2017 Suburban with 101,000 miles. Recent problem - I am pulling out of my driveway which has a slight incline. I pause at the top of the driveway to check traffic, apply pressure on the brake, get the hill assist notification on cluster - when I go to pull out onto the street - sometimes the transmission will not shift into gear and I will just rev the engine? Had the transmission serviced maybe a month ago and new spark plugs and wires. I do have a RANGE AFM plugged in - but that should not affect it? Any ideas?

Thanks in Advance.