@edumorlom,

This is something that you can do with some of the latest Decos, but it is a limitation of the requirements put on the network from 6E. 6Ghz offers additional features and encourages the use of a different/higher security method - which makes it difficult to mesh them all together, while also providing support for older legacy devices. 

I would take a look at this reddit post where this exact discussion occurs: https://www.reddit.com/r/TpLink/comments/131w7o3/tplink_6ghz_mesh_is_a_lie/ and there are some great insights and troubleshooting steps provided.

You may also always set your 6Ghz to have the same name, which will cause your device to choose between connecting to your 6Ghz network and the mesh.