@Dennis1234
Did you pay attention to the internet LED on the AX73 when there is no internet access but shows connected? Will the LED turn orange?
Who is your ISP? What kind of WAN Connection Type you are using on the AX73? Please check and ensure you get a stable internet connection from your ISP by connecting a computer to the ISP modem directly bypassing the AX73.
If the modem connection is stable but the issue persists on the AX73, please try to change the internet DNS settings on the AX73 to some third parties, such as Google's 8.8.8.8 and 8.8.4.4, or Cloudflare's 1.1.1.1, then monitor again.
It's also suggested to go through the troubleshooting suggestions in the following thread to locate or fix the issue:
Router Disconnects from Internet