@Kevin_Z  I check the Windows 10 Wireless Connection Status. It states there the link speed is 2.4Gbps when I first power on the router and get connected. But slowly over a few hours, this speed decreases to a few hundred Mbps. If I power off and power on the router again, it goes back up to 2.4Gbps.

This has nothing to do with my Internet connection speed. My Internet connection speed is 500Mbps and I am still able to get this speed when the router slows down. The problem is file transfer speed to another PC has decreased.

The speed seems to be more stable if I manually select a fixed channel and set to maximum bandwidth for all 3 bands. Setting channel selection to Auto seems to produce this problem.

The problem with this setting is that after a while the WiFi disconnects and the client cannot connect to the router again until the router is rebooted. I hope there will be a firmware update soon to address this.

Same issue experiencing at my end. I am getting 250-300Mbps at max WiFi & lan speed from the router compared to Netgear AX12 & MK60 which is giving around 400Mbps on gigabit internet from ISP. After sometime, speed drops to10-20 Mbps. Only way to recover the speed is to reboot which is patchiing the problem temporarily. Downgraded firmware per customer support but no luck.

Not sure what else can do before returning it.

@Kevin_Z  please resolve this issue. when will be the release of new FW update?

After three months fighting with my cable provider; making them replace their coax drop, spending money on  a new top-of-the-line DOCSIS3,1 modem, we finally came to the conclusion that the (supposedly gaming) AX1100 router is to blame. And until TP Link fixes it, we will have to reset it every day! Insane

my Internet service is 600M/20M and after a reset we  normally measure  556M/18M; then it starts to go down and settles at a mare 2M/1M and huge latency, so it just doesnt work. 
 

It also has the problem reported by others, that after a month it blocks some WiFi clients. They show as connected to WiFi but zero throughput. 
 

it is back all default settings 

I'll give it a month or so, before I send it back

@Polito @Kevin_Z 

man, if ever the same thing happend to me ill be sure to go crazy.2m/1m return the item for exchange bro. its definitely deffective. lucky for me, it never happend. my plan is 1Gbps and im reaching 750Mbps at max. its not consistent though. the connection is consistent at 900Mbps if directly connected to the modem. my asus ax88u is consistent at 750-800. idk why this router is giving me fluctuating results at 550-750Mbps. tests are done next to the router so interferenace should not be an issue.

@Kevin_Z 

that is actual WAN speed, measured by the router itself (see picture) or using Speedtest on my wired AppleTV or using an Internet test set.

the other problem with the WiFi side is that my tablets or phones get blocked. They are connected but no throuput