My note 20 Ultra arrived 3 days ago and Im facing terrible wifi issues. The speed is stuck at 29 mb's. I have my old iphone and its getting 400+ easily. I tried straight from the modem and than bought google nest wifi as well and still same issue. This is my first samsung phone and im pretty unhappy with it. The camera is making my skin yellowish in low light. If I put the phone on silent and turn the vibration, the vibration is too low to even know about the messages I received. Tried all the vibration, camera and wifi settings still same issue. I get good wifi speed after restarting my phone for couple of minutes and after that again getting the same issue of 29mb at max. Its frustrating.
I get around 150Mbps on my Wi-Fi... maybe it's some kind of QoS issue? (Quality of Service setting...) Check your router's settings and if it's enabled, try turning it off. It always caused all kinds of issues for me.