Been banging my head against the wall for over a week on this, so hopefully this is the right place for a solution!

Since upgrading my service about a week ago (Xfinity, 400/10) I've noticed the wireless downloads speeds coming from my router have dropped significantly. Before the upgrade (100/5) I was getting at or near 100 down on almost all of my devices pretty regularly, sometimes even above. The real life test is whether or not we can stream Netflix on our TV downstairs which has a crappy WiFi connection, it was never a problem. After upgrading our upload speeds are all at or over 10 on all devices, consistently, but our download speeds are 20-40 on 2.4GHz and 60-80 on 5GHz. Crappy downstairs TV can now only stream Netflix for a couple minutes at a time before spinning wheel of death.

I know "there are many variables to the speed of your WiFi" but I would expect at least 50% of the 400Mbps via the 5GHz when standing directly next to the router.

We had a tech from Xfinity come out and examine our connection, and it's healthy. I get 400 down consistently when I directly wire the modem to my PC AND when I directly wire the router to my PC. This is only a WiFi download speed issue.

I feel like I have tried almost everything and I'm now just considering scrapping the router and buying a different brand. Here's a hit list of some of stuff I've tried:

• Firmware update to 2.0.1 Build 20200819 rel.31399(5553) (at TP-LINK's suggestion)
• Changing DNS settings
• Turning off Smart Connect
• Changing channels on both bands based on WiFi analysis
• Testing signal all over the house (it is strong)
• Changing channel width on both bands
• Toggling QOS on and off
• Disabling all ALG
• Toggling IPv6 on and off
• Handful of factory resets
• Countless reboots of modem, router, and devices
• Disabling WMM on both bands
• Disabling NAT Boost on both bands

Any help would be greatly appreciated before I yeet this thing into a lake at speeds faster than what I am currently getting. Thanks!