Hi yes I had a similar problem with slowness over points on a couple off Bachmann 08's with their chips fitted. Would happily work on layout then when they hit the frog controlled section by DCC 80 would slow right down and then pickup speed. I cured it by fitting Gaugemaster chips!!!
But had no other problems with them and now will always incorporate in a layout, saves the hassle of centering point motors switches!
NCE Power cab system.