glitching
I had the same exact same problem but with a SXX V2 Comp. About a year ago I was running a M11 with the 75mhz crystal receivers. I had three receivers in three cars for three different applications with no problems. I ran an SPX boosted 13.5, SP GT 2.0 for TC 17.5 stock, and one in my NT1 nitro car. Anyways my Speedpassion took a dump so I bought the SXX V2 Comp for 17.5 TC stock. Well for some reason the car worked great within a 20ft but had major glitching beyond that. I hooked up a 2.4 ghz system to that ESC and it works great. Long story short, I ended up buying a 2.4ghz radio so I could run it. So if your still running crystals in your receiver that may be the problem.