I had something similar with both of my 24.160... it works almost like a air plane ESC, just like Serum said, it would slow the motor down if you went down with your throttle... I've tried adjusting the freewheel option also, but it didn't do anything for me.... You have a lot of problems man, wish I could help you out more..
lol I am having issues with random braking....I think the update will fix it...I have 2 MMM's on order cause I don't have time being at home with kids to spend hours to get it to work correctly.....my time is scarce these days