Hello @starun
Thank you for posting on the TP-Link Community.
Firstly, please ensure you are running the latest firmware on the AX1500, you may hit the Check for updates on its web interface to confirm, or you can download it from the official website:
https://www.tp-link.com/support/download/archer-ax1500/#Firmware
Please determine if you are talking about the 2.4G signal or 5G signal, if the firmware upgrade doesn't help, try to run a Wi-Fi analyzer to verify which 2.4G/5G channel is clearer, then try the channel, you can also change channel width to 80MHz for the 5G and 40MHz for the 2.4G, change security to WPA/WPA2-Personal, WPA2-PSK/AES, then reboot it and confirm.
You're suggested to check these tips to optimize the router location as well as other environmental settings:
https://www.tp-link.com/en/blog/87/6-tips-on-where-to-place-your-wireless-router-for-the-best-signal-coverage/