1. Network Equipment - Chunghwa Telecom Optical Generation(ADSL)

2. Wiring Method - Modem - AX12(A) (using dial-up internet); First, pair AX12(B) and AX12(C) using Wi-Fi near AX12(A) to form a one-mesh connection; connect the network cables leading to the 2nd and 3rd floors to the LAN port of AX12(A).

3. Take B and C to the 2nd and 3rd floors respectively and connect them to the WAN port using network cables. At this time, the Wi-Fi cannot connect to the internet; connecting to the LAN port allows connection, but the Tether App shows that A is wirelessly connected to B and C, not via Ethernet backhaul.

4. The connection works very well initially, but B and C frequently disconnect, and the internet LEDs on B and C intermittently turn orange; the phone must delete the original Wi-Fi settings and log in again to connect.

Where is the configuration incorrect, and how can it be resolved?