Virtual gears frustrating

Hi, i use a Wahoo kickr move, with climb, and Zwift play. When using virtual gears on steep climbs such as the Alpe, or climb portal climbs, i can feel the resistance changing enough when it shouldnt, that it feels like wheel slip on a wheel on trainer, the resistance also drops when near a rider, it feels sometimes like you are drafting a bus! Also, occasionally the resistance drops to what feels like a couple of %, when it should be 10% or more. All of the firmwares etc are up to date, ive tried big ring, small ring, unplugging the trainer to re-set, i cant get to grips with whats wrong, and its annoying enough to stop using the virtual gears.
Any ideas, last thing i did was pwer smooting on the trainer to try next ride, but other than that i’m stumped, and if i had hair, it’d now be gone!
Thanks.

I don’t know what’s up but Wahoo power smoothing is for ERG mode and won’t affect terrain simulation.