The thing is my wifi network is from the same router as eth and it works fine .. in fact everything else on AppleTV works fine (with wifi) besides Netflix app.. which in fact shows: "something went wrong- try again later" message without any error number.. I just figure it out problem myself.. I guess it might be some Netflix problem that I am coming from within eth and then from wifi on the same device so maybe it was blocked.. like when you try use VPN..
so maybe if I "factory reset" AppleTV - which will erase all Netflix signature data from the device - it will start working again on wifi .. ?