Solution is in the original post above. open powershell as administrator, copy and paste one line at a time from below, and press enter after each.
I just spent a couple hours trying to fix slow wifi on my XPS 9310 with Killer Wifi 6 AX500-DBS. I was only getting 20Mbs in a speed test and my phone phone could get 400Mbs. After performing the commands below, my XPS 9310 improved to 400Mbs: open powershell as administrator, copy and paste one line at a time from below, and press enter after each. After each command, the powershell will say "ok" for most of the commands. Some may not be compatible, which you can ignore, and move to the next one. Here are the commands:  
Solution Slow Wifi XPS 9310 Killer Wifi 6 AX500-DBS 20Mbs speed test, phone 
speed 400Mbs