Você pode tentar mudar para diferentes canais de 5GHz que não receberão interferência do radar do governo. Verifique este (mesmo que seja um hardware diferente do seu), especificamente a pergunta abaixo:
Why does the WNDR4300 only support 4 channels in 5GHz if the wireless region is Europe, only 8 channels if wireless region is United States at "Up to 450Mbps"? Other 5GHz channels are DFS channels. There are government radars working in those channels. Without passing DFS certification test, we are not allowed to open those DFS channels. We are doing DFS certification and we can open those channels by releasing new firmware after we get DFS certification in the near future. You DO NOT need to change hardware, but just upgrade the WNDR4300 firmware to the new one which supports DFS channels. However, you still need to make sure your 5GHz wireless adapter can support DFS channels. Otherwise, you still can't use those channels.
Então parece que o firmware atualizado abriu esses canais, mas com a restrição de que se o radar fosse detectado nesses canais DFS, ele os bloquearia temporariamente ou mudaria o canal.
Uma lista de canais habilitados para DFS está em este documento da Cisco. Talvez você possa experimentar um canal que não esteja nessa lista e ver se funciona melhor.
Dynamic Frequency Selection Channels When a DFS–enabled radio is operating on one of the following channels, the wireless device uses DFS to monitor the operating frequency and switch to another frequency or reduce power as necessary:
• 52 (5260 MHz) • 56 (5280 MHz) • 60 (5300 MHz) • 64 (5320 MHz) • 100 (5500 MHz) • 104 (5520 MHz) • 108 (5540 MHz) • 112 (5560 MHz) • 116 (5580 MHz) • 120 (5600 MHz) • 124 (5620 MHz) • 128 (5640 MHz) • 132 (5660 MHz) • 136 (5680 MHz) • 140 (5700 MHz)