Mine did something similar a few months after I bought it. When I would hit it hard and then let off, it felt like it shifted into neutral and wouldn’t shift back into drive until I stopped and put it in park. Then it would drive normally. Turned out, I was low on fluid because the conductor plate connector was leaking. Filled it up and ordered a new connector. Went to install it and broke the screw. Ordered a new conductor plate (Ebay) and it came with a new connector. Installed and it was stuck in limp mode. Got fed up and took it to a trans shop. He replaced the conductor plate and connector with new Mercedes parts and all is well. Long story short, low fluid. Why is the fluid low?