@Donnei_Tsai 

Hi, Thanks for your message.

I see both Band 1 and Band 4 are supported in Taiwan.

Do you have any mobile devices that use Band 4 only on 5GHz? Can I have their model numbers?

Wait for your reply and best regards.

  @Donnei_Tsai 

Hi, thanks for the update.

Both Deco X60 and Deco M4(US) in Taiwan don't support band 4.

I think most of the local-purchased devices also use band 1 on 5GHz. Supposing you can set Deco to band 4, then you might notice other 5Ghz clients unable to detect the Wi-Fi.

For the ASUS AC-56 USB WIFI NIC wireless adapter, I think the supported band follows the region code of the computer. The hardware itself is sold around the world and It doesn't mention band 4 only via Google search.

Thank you very much and best regards.

  @Donnei_Tsai 

Hi, It might depend on where you purchased the Deco. The general EU version only supports Band 1(some models might also use Band 2/3 over 5GHz).

The local WiFi regulation in Bangladesh/Indonesia states only band 4 is allowed so the local-purchased Deco will use band 4.

So far, Deco still does not support manually changing wireless channels.

You could try another wireless adapter, such as Archer TX20U which also supports WiFi6 like Deco X60.

Thank you very much and best regards.

  @Donnei_Tsai 

Hi, No, like Deco X25/ Deco X55/Deco XE75 and several other models, their US version does support band 4.

The supported bands usually follow the region code embedded in the hardware and I have not received any news of further plans to support other bands.

Thank you very much and Best regards.

  @Donnei_Tsai 

Hi, there hasn't been any document yet. But We can assure you that the locally-purchased Deco complies with all local regulations and works with most mobile devices.

Thank you very much and best regards.