For this issue, please check and try the following points:
1. Check if you have installed the latest version mBlock APP.
2. What's kind battery do you use for the mBot? If they are normal non-rechargeable AA battery, please change brand new batteries have a try.
According to our test and research, it is suggested to use rechargeable Li-ion battery or rechargeable nickel-metal hydride, nickel-cadmium which can be bought from amazon or local shop. Or Alkaline battery with good quality like Energizer, DURACELL.
3.Upgrade firmware for mBot refer to this document first, then test again have a try.1. How to Upgrade Firmware for mBot.docx.zip (690.6 KB)