I previously had with IOT devices on the same net doing exessive broadcasts/multicasts. Also on your WifiAP (if you can) setting DTIM from 1 to 2 might help, as the phone has a longer "inactivity" time until force to receive new data packets by the WiFi AP.Does anyone have a problem with big battery drain while being connected to wifi? It's happening to me since two days and God knows what's going on. I got 1h30min SoT on 15% (100% to 85%) and after that drain comes in, losing around 3%/h while doing nothing. I appreciate your tips
For a start: Try monitoring the WiFi battery usage on a blank ("only providing internet connection") WiFi SSID - preferably on a separate network.
My WiFi battery usage is normal after 22 hours of testing the recent Android 11 based PixelExperience Plus release on Xiaomi mi 8.