@Waseem123 

Do you mean you bought the router 3 months ago, the Wi-Fi range was good, but now it decreases? If that's the case, you can try to run a Wi-Fi analyzer to review the channels in the network, choose a clear channel, and change the channel width to 20MHz for the 2.4G, and change it to 40MHz for the 5G, reboot the router and confirm.

You can also refer to this article to try to relocate the AX50 as well as the antenna on it, then monitor if there is any improvement:
https://www.tp-link.com/support/faq/468/
https://www.tp-link.com/support/faq/469/