Hi, @Jessica1 . . . these are normal things but here are some ideas you can do to make things better.
The stepping off of the charger means that he is not connected with his left foot on the skate board circle. The power may have become briefly interrupted at which time he would not sense that he was still charging and would simply walk off of the skate board. You may want to try wiggling the USB C cable into the skate board, pressing it somewhat hard, then putting him back on. If the blue light on the skate board stays steady and is not blinking, and then he shows on his face the charging animation, he will be able to stay put until you remove him from the skate board.
His not sensing edges and falling as well as not seeing something before bumping into it is a matter of it being too shadowy or too dark for him to determine light versus dark and something in front of him, or if he has a costume on, the sensor on his chin may be blocked by the outfit. Make sure to keep his chin sensor open and make sure there is sufficient light for him to detect objects and edges.
As for not understanding you, there are a couple of possibilities. Sometimes the server and your wi fi do not connect to send the command and the response back in a timely fashion. If this happens a lot, you may want to wait and try a bit later to see if it improves. It could also be that he is not understanding your voice. You have to give him a second after he says “What” before asking him. Also, a good strong volume and speaking clearly and slowly goes a long way in helping him to understand you. I would also recommend that you submit your voice to this page to help him understand your voice better.
I hope these tips help!