Short Answer - your drivers...
I put together this short video where I was troubleshooting my own laptop wifi issues when I realized that the Dell and Microsoft sites claimed my drivers were current.
Then I went to Intel and my drivers were in fact a few versions behind. I upgraded my drivers and things got faster and more stable.
I've seen old Wifi drivers do the strangest things from; Blue Screen laptops with certain configs, cause performance issues and generate stability complaints, so I thin this simple point shouldn't be trivialized.