@Phettsack : Try a reset to factory default of the controller and add it back again, just to see if that makes any difference. Aside from adding the controller to a 5Ghz WiFi network rather than a 2.4Ghz one there isn't much else that can be done AFAIK.
Thanks for the quick answer! Does the controller communicate only via WLAN with stadia or is there some bluetooth data exchange with the chromecast, too? Because I bought a second chromecast ultra on sunday and since then I maybe have this problem, but I haven't played few days before to be clear about this.
I just found out in my router that the chromecasts get a IPv6 address but the controller does not. Is it really an IPv4 device only?
@Phettsack : Yes, comms is via WiFi to Stadia, Bluetooth is only used during the setup procedure to allow the WiFi details to be applied. I've not checked to see what is happening with v6 addresses, I'm still in the dark ages and my ISP is still throwing that bunch of balls up in the air and trying to decide which if any it wants to catch.
Yesterday evening I played Farming Simulator and had no problem at all. I'll keep an eye on it.
@Mad_Dog_Bravo You have an idea how the controller is sending the movements? TCP or UDP?
I guess its UDP because it makes no sense to resend a package.
@Phettsack : I haven't run a packet capture to examine which protocol is being used, although the guidance is that TCP/UDP ports 44700 to 44899 are used, but as you have already alluded to, it is very unlikely that TCP is being used and UDP would make more sense for the controller, but that is purely speculation on my side and I have no concrete evidence to back that assumption.