@Lbheath 

NAT Boost you might not need? Although good for speed down above 100Mbps, until you speed is over 200Mbps you'll not see any advantage. See https://routerguide.net/nat-acceleration-on-or-off/ for instance (NAT BOOST = NAT ACCELERATION).

WMM probably should be enabled as well, worth reading, https://www.smallnetbuilder.com/wireless/wireless-features/30938-dont-mess-with-wmm.

One question, is this for both wired and wireless that you are experiencing low speed or just wireless?

If just wireless, did anything change on the device(s)? It is on all devices or just one? Both 2.4 and 5Ghz or just one?

Have you tried changing SSID channels?

@IrvSp 

Hello, thanks for replying, but to answer your question I get the same level of download speed of around 20 mbps on both wired and wireless connection. 

Lbheath wrote

I also tried switching SSID with the same outcome, still only getting 20 mbps download

@Lbheath 

Well, at this point I'd suggest RESETTING the router and just testing with the wired connection. Getting the proper speed, make the rest off the needed setup changes. Still failing, contact Support. Might be a h/w issue.

@IrvSp 

Do u mean do a factory reset and then do my full setup again?

Lbheath wrote

@IrvSp 

 

Do u mean do a factory reset and then do my full setup again?

@Lbheath 

Yes, but realize I am grasping to figure this out too. I also do not work for TP-Link nor have any official standing. Just a plain user like you, with possibly more networking  experience.

Do so will wipe everything out. I probably should have suggested you back-up your resetting so you can restore them if you wish. If you are un-sure of changes you made, take screen shots of all changed pages for reference.

So, reset it to Factory and test. Doesn't work any better, contact support. Since you are connected to the modem via cable and the router should have NO changed settings, it might be easy for them to determine the cause. Oh, one more test, use a different cable between the device and modem to router. Could have a cable go bad or even not be secure in a socket causing a problem.

@IrvSp 

I appreciate your help. Somehow my somehow my speed gets worse each day, last night my mbps was down 13 up 19.  Seems crazy, I have never seen the upload higher than the download.

@Lbheath  Seeing the same here. Bypassing the router going straight to the modem is consistently 100 Mbps down, 11 up. Going through router (wired or wireless) I get anywhere from 1 to 23 Mbps down but always 11 up. I've updated firmware, factory reset, modified ssid, changed channels, changed refresh rates and still get erratic, unreliable behavior. throught he router.  I'm commenting 1) to follow the thread in case you find an answer, 2) to follow thread in case I find an answer, and 3) to let you know you're not alone. :)

@Lbheath 

Only other thing I'd try is INDIVIDUAL devices? One at a time and see if ANY get the correct speed? Make sure ALL are disconnected from the router and only connect one while testing it.

If you have a USB connector, disconnect that device as well.