AVM Fritz: WLAN Mesh with Powerline Repeater does not work - Part 2

A month ago i tried to get the new WLAN mesh running with my Fritz!Box 7490 and Fritz!Powerline 546E.

Some days ago AVM release a new firmware for the 546E:

But even with the new firmware the powerline adapter does show up with the "mesh symbol" inside the home network overview:

I am wondering, if the WLAN mesh only works by using the powerline connectivity. AVM support pages show up the following advisory:

As you can see: Only the secondary powerline adapter shows the "mesh symbol".

Inside the networking overview my 546E is registered in this way:

Which is definitly wrong, because it is connected as WLAN bridge to the Fritz!Box without any powerline technololgy...

Hopefully the next update may fix this.