WiFi drops for no reason

[bomberb17]

I have an Acer Aspire E15 E5-574G-54Y2 with Atheros QCA9377 and Windows 10 Pro. At home I'm connected to my 5Ghz network and everything was running smoothly, but now I'm away for the holidays and when I'm connected to 2.4Ghz networks, the connection suddenly drops for no reason. It won't come back, and I cannot scan any networks (including the one I was connected to) unless I go to "Network Connections", right click on the QCA9377 adapter and select "Diagnose", or disable/enable/change driver from the Device Manager. I tried with many drivers, starting from 12.0.0.203 up to 12.0.0.722 (as well as the one from Microsoft) and same problem happens. "allow computer to turn off device to save power" is disabled. Played with various options in the advanced tab in the device manager but same problem. I even tried making a "Network reset" from Windows 10, but problem comes up again after a while. I connected an external Alfa wireless NIC which works perfectly. The same problem occurs in two different networks in different areas, where all my phones/tablets work perfectly. (so this is not a router related problem). Any thoughts on solving this?

[nil]

I'm assuming you've seen this epic thread - https://answers.microsoft.com/en-us/windows/forum/windows_10-networking/qualcomm-atheros-ar9485-wifi-disconnects-randomly/bb7fd0ef-455d-4e1e-b973-6632791e0cc3

Everyone seems to agree it's a problem that was introduced by a Windows Update. Some users say turning the hardware wi-fi switch off then on is a quick fix. Some say locating another driver and manually replacing it worked. Others had some success changing the power saving settings for the adapter (device manager -> select wifi adapter -> power management -> uncheck allow computer to turn off the device). Have you tried any of these?

[bomberb17]

Thanks for the link, although it is about a different Atheros model (still the solution might be common).
My laptop doesn't have a hardware switch.
As I said in my original post, I have tried 4 different drivers and I have turned off the power management box. Changing driver resets the wifi connection (so it comes up again) but the problem comes up with all drivers after a while.
I'm considering myself an expert user, and I have never seen anything similar before. The strange thing is that the card looks totally disabled after the wifi drops, so it does not pick up any SSIDs at all. I even tried to change the MTU of the WiFi card, again with no success.
I also tried running Wireshark in the background to see what's going on, it looks like there are lots of TCP retransmissions just before the wifi connection drops.

[nil]

I'm sorry for missing that information in your original post.

Have you looked at power options in your BIOS that might affect the NIC?

[Geek-9pm]

This is a method to help identify the nature of the problem.

Go to a local store and find a USB Wi-Fi adapter. Take note of their return policy.
I believe Windows 10 wail use the device without need of a driver.  My experience that Windows 10 now includes drivers for most of the popular USB Wi-Fi gizmos.

Expect to pay under $15 for a generic.

If it does notwork, take it back for a refund.

[bomberb17]

There is no other BIOS setting for the NIC, apart from disabling it.
I already have an external Alfa Wireless which works flawlessly, but I want to fix the built-in one and work with that..