Last week, we reported that Microsoft's new Surface devices were experiencing several issues, one of them being slow Wi-Fi after waking from sleep. Now that time has passed, it's clear that this issue is one many are experiencing.
Numerous posts on Reddit and the Microsoft Answers forums suggest both the Surface Pro 7 and Laptop 3 are affected, with the culprit being a faulty Intel AX201 driver. These were custom developed by Microsoft and Intel, but some users report speed loss of up to 480mbit on version 21.40.13.
The company is yet to officially acknowledge the issue, and Intel has also been quiet. However, some customers report that Microsoft Store representatives are aware of the problem. With hope, the experts will soon be working on it.
There is a possible mitigation, but first, it's important to stress what not to do. Users should not install generic AX201 drivers as they may experience issues and be unable to switch back to the custom ones. Re-installing and updating are also options, but there's a much simpler way. According to Reddit's u/Wiidesire, the problem is as follows:
“The new Intel AX201 adapter has 2×2 MIMO, basically double the antennas for double the speed (if your router supports it). Now in standby Dynamic SMPS disables one antenna and the other antenna goes to a low power state. However, the bug is that after waking up the device from standby, the second antenna is not activated and the other antenna remains in the low power state resulting in severely reduced speeds, higher latency.”
Hence, changing the adapter settings from ‘Auto SMPS' to ‘No SMPS' appears to fix the problem. This can be found under hardware manager > network adapter > Intel AX201 > Advanced >MIMO power save mode.
Additionally, you can set ‘Disconnect from network' to ‘Always' in Power & Sleep settings to reduce the standby drain caused by toggling the power save mode.