@TP-Link Thank you for your reply. I am aware that VLAN tagging is not required (having the Deco devices in AP mode) to isolate the Guest Wifi network from the main network. I can confirm that access...

I own a set of X60s and am equally frustrated by the fact that we can't use VLAN tagging of the guest network when the devices are in AP mode. @TP-Link_Deco we need this!