Windows has been known many times over to interfere with networking in Linux. There is a possibility that may be a factor. In Windoze driver advanced properties see if you can find a wifi power saving option. Be sure to disable it if it is present in Windoze.
Then power down completely and remove the battery from the laptop and disconnect the power cord. Then with the power sources removed press and hold the power button for 20-30 seconds, Let the laptop sit for a few minutes with no power, then reconnect the power cord, but not the battery. Restart and boot directly into Garuda. Check you speeds.
There is a possibility the linux-firmware is a component to this problem but we'll leave that for later.
The next thing to test is changing the iwlwifi driver options (which I will explain in my next post below).