@MDByr 

So to start there is a difference between the throughput speeds that are advertised and internet speed.   Throughput is the rate at which clients, like a computer, communicate within the network and with the router.  Internet speed is the rate at which a client communicates outside the network.   Internet speeds are based on several factors.  

• Client distance from the router
• Network congestion
• Network interference, like from other network in the area
• Barriers, such as walls, doors, etc
• EMI, which is electric interference. This is from sources like appliances, microwaves, CFLs, etc.
• Hardware.  Like the network adapter in the client (computer, tablet, etc)  

So although you are not seeing the full 1Gbps on your client you might be getting what is considered good speed for that client.  

  @MDByr 

are your devices and router using 802.11n? That may be your issue. Be sure to use AC or AX. 

  @MDByr 

Are you running the speed test from a computer or device or are you running the speed test from the router itself? Also, looks like there is a firmware upgrade available. I was having other issues with mine and did a firmware check from the router and found an update released this month (08/2023).