OnePlus 8T running a open port 5555 named as Freeciv which is a major security threat . It is basically a port for Android debug bridge mode on the WiFi as per Internet . So anyone can take over your phone when that port is open and when you connect to a prone WiFi which has hackers
Do report at your side.
You can use Fing on a different mobile and scan the 8T on the same network
Or else nmap will also do
Guys do check with your devices also
The new update has battery drain as reported by OnePlus Forum. Hopefully they will fix it with a counter update. Also Widevine L1 is not there yet on this device. L3 is there. Or maybe it is reduced to L3 on the new update