DAIKIN split duct problem

[Eep]

I have a problem with DAIKIN split duct 10 PK .... the problem is that every unit is running, it always happens frost on the suction line including the accumulator, is who should I do? I've done flushing the evaporator, pipe installation, replace the filter drier, but still going frost for the solution ... please help .......

[JoeAT50A]

Your return (suction) is very slow, due to long piping or kinks in piping wise.
Your ducting are too long, filters or coils are dirty, static pressure weak. Try to take out either return or supply filter to test. If slightly improve, then problem will be air side, not system.