Contradicting information regarding Mesh APs and roles

https://docs.sophos.com/nsg/sophos-firewall/18.5/Help/en-us/webhelp/onlinehelp/AdministratorHelp/Wireless/HowToArticles/WirelessDeployMeshNetwork/index.html#create-a-mesh-network-and-configure-access-points

Here it says "You must designate at least one access point as root and one as mesh access point."

https://docs.sophos.com/nsg/sophos-firewall/18.5/Help/en-us/webhelp/onlinehelp/AdministratorHelp/Wireless/MeshNetworks/index.html#general-settings

Here it says "For APX access points, there's no need to specify the mesh role. If the mesh-enabled SSID is pushed to two APXs, the one with the existing Ethernet connection to the Sophos Firewall becomes the root access point. Once the mesh-enabled SSIDs are pushed to the APXs, it’s advisable to restart them."

The first seems to be true, but there is also a glitch in Firewall WebAdmin: First the role is asked, after selecting the AP the dropdown box disappears.

Annoying.