@Ed-win , the option is available at Wi-Fi settings, after upgrading to the latest firmware.

An update on the issue, apparently solved after last firmware update as it's working for me: https://www.tp-link.com/pt/support/download/deco-m4/v1/#Firmware: 3. Added isolation switch for the main...

Anyone?

Hello, Anyone from tp-link to comment here? Thanks

Hello, More than eight months passed since the last firmware that implements "Guest Network" in AP mode, only that the "Guest Network" actually don't comply with the minimal requirement, be separate...

Thanks for the clarification, @Kevin_Z .