I have been experiencing WiFi speed issues on my old S10+ since the latest update, if I remember correctly. I have two WiFi 6 and two WiFi 5 APs and the issues is present with all of them. The problem is that the connection sometimes slows down to about 50mbps, rarely also to 4mbps or less. In the settings it still shows me the full speed. Turning WiFi off and on works most of the time, but sometimes I have to wait till the speed returns back to normal. It is the WiFi speed that is low not only the internet speed. I tested the speed with iPerf3 and Ookla Speedtest. None of the other devices on the WiFi have this problem. This issue is described multiple times on different forums, but no solution was found. I thought it would have been fixed on the S20+, but I got a S20+ 5G Exynos about a month ago and still have this problem. The S20+ has the latest updates. What I tried: 1. Forgetting the network and adding it again 2. Turning off MAC randomisation 3. Turning off WiFi scan throttling 4. Turning on WiFi safe mode 5. Disabling the automatic channel configuration of the APs and setting them far apart 6. Disabling location and location services 7. Turning off adaptive battery 8. Enabling enhanced processing 9. Wiping cache partition 10. Soft reseting the S10+ 11. Changing encryption from WPA2 to WPA2/WPA3
EDIT: The issue came back today. The connection drops to about 50mbps. Then I disable and enable WiFi and it works again for some time.
It shouldn't need the latest features, because there are standards. However, your reply brought me to the idea of checking the encryption, and I changed it from WPA2 to WPA2/WPA3, and now it seems to be fine.
Behavior like you describe is commonly associated with TCP congestion, though it can't be proven without more detailed investigation. Congestion is a normal behavior for TCP in the present day. Resolving congestion would normally involve device tuning that's not practical on Android devices. Almost all of the solutions you describe would reduce congestion, mostly by forcing current connections to be re-formed. The ones that make sense to persist are 5., 8., 7. and 3. in order of my preference. Perhaps you just have too many apps running (including background) that use TCP connections to external hosts. It doesn't take much, imagine the TCP traffic required for a live weather app that continually downloads weather radar images in the background. I'm not saying you have such an app, but you might consider what network traffic might be required by the apps you are running, foreground and background.
EDIT: The issue came back today. The connection drops to about 50mbps. Then I disable and enable WiFi and it works again for some time.
For some reason I had my APs set to WPA2. I set them to WPA2/WPA3 and so far I have no problems anymore. I have to test it in the coming days to see if it remains stable.
Good to hear. Unless you have any devices that only support WPA2 then it would probably be even better to have the AP not use mixed mode and use WPA3 only.
