My setup is :
Tacx Smart Neo
Assioma Duo pedals (power meter)
Ant+ USB key
Garmin Edge 1030
Samsung Galaxy S10+
PC using WIndow 10
SInce few weeks, I encounter an random power issue.
It always appened after a power peak if I release the rythm (and power level), zwift is displaying, for ex.,200W but in reality the power applied is 50 to 70W over (seen on the Garmin using the Assioma power meter), the only way to correct this problem is to release the Ant+ link with the controller in Zwift and connect it again, sometime it is not easy if you are racing in the Pretzel 
I don’t know if someone already had the same issue?
Thanks