07 Acura MDX occasional vibration 25-40 mph accelarating


I have a new to me 07 MDX(82k miles) with a 5 speed automatic. Its my first automatic vehicle ever as I have driven manuals for 20yrs. Regular servicing at Acura dealer by previous owner including auto fluid at 65k miles. Also some sort of update applied to transmission at 50k.

If I drive it easy from 25-40MPH sometimes I get a vibration accelerating as it shifts the gears. It seems to lug the motor a bit but I believe trying save fuel. The vibration is not always there. If you accelerate moderately - hard it shifts perfectly. Also at lights it seems to vibrate a tad but maybe that’s absolutely normal for an automatic vehicle. I can shift to N and its just like my clutch car very smooth.

Not sure if this stuff is just normal for an automatic or I should investigate further.