So Freda, now you know why you did feel it the same.

So you must have had also bad range.
Yes, that Go+ works weired, but I must say it worked for me, when I tested with M510. So should be working also on M820. What I noticed it didnt sometimes read the settings, I had to click forth and back and then it went updated. Did analyse CAN traffic from display, It was sending setup packets to motor.
Put acceleration on full.

It is the steepness of startup current. For a short period of time (<2s). So dont expect any difference in acceleration from lets say 20kmh to 30kmh.
You have 9A. Try 12A. Should be peaking 600W

Very good for such a small motor.