In fact it looks like the same issue as others have mentioned on this forum (the slow degrade of internet quality) is still taking place despite having the "new" firmware.

Also the oddball ~2-20 Mbps speed tests are the random instances where TP-Link has had my phone connect via 2.4G instead of 5G.

Anyone?

@Wojtnic 

1. Disable smart connect you can choose what network to connect to rather then the router.
2. Test other wireless devices and with the 5GHz network, not the 2.4GHz.
3. Of the seven devices make sure other devices were not downloading or using the available bandwidth at that time.

@Tony 

1.) Smart Connect has been disabled this entire time

2.) I have done that as well. My work laptop couldn't even connect to the speed test website and my personal laptop only gets ~350 mbps as well.

3.) None of them were. They are devices like a Nest thermostat, google home, 2 amcrest cameras, etc.

Furthermore, if this router is that sensitivity to something else using a tiny bit of bandwidth, that is alarming.

@Wojtnic 

Are you 2.4GHz and 5GHz both named the same? You mentioned your phone keeps connecting to the 2.4Ghz rather then the 5Ghz. If not, forget the 2.4Ghz network so the phone will not automatically switch. What else could be happening is you are moving too far from the 5GHz signal so the phone jumps over to the better signal.

The third point was simply a suggestion to try given the situation, not a statement of the capability of the router.

In any case, I would suggest contacting our support to looking into your issue further, having that speed with 1 gbps internet is unusual.

Live Chat: link
Phone: link
E-mail: link

@Tony 

They have the same "basename" but are not identical (i.e. Internet 5G and Internet 2.4G)

To the second point, that is what occured (i.e. I moved away from the house on a walk) however, upon returning, my phone does not reconnect to 5G unless I tell it to. That wasn't the old behvior when using the Linksys Router.

I do have a case open to TP-link that I'm waiting a reponse on.

@ArcherC8 

Not using a modem. I have fios so the signal comes directly from the ONT box (which I guess is a modem technically) to the router. Router is getting speeds in the ~600-700 mbps.

My desktop PC is getting similar speeds which is connected by Ethernet.

@Wojtnic Now even my wired connection is getting worse....Following TP-Links suggestion of: 

for 2.4 GHz> channel : 1, 6, and 11 width : 40MHz
5 GHz > channel 36 width : 80 Mhz
after that check again the speed

Resulted in:

Router speed: 668 mbps up | 673 mbps down 

Hardwired PC speed: 395.53 mbps up | 353.43 mbps down 

Wireless PC speed: 253.34 mbps up | 267.02 mbps down 

How does this router continuosly to degrade every day??

@Wojtnic Sorry to hijack your topic but i wanted to know if you have solved this issue? I got the same troubles with 2 samsung devices (S9+ and Tab S5e) and wifi with my c5400x