I found the issue explained in the thread MuSo 2 WiFi problems
It appears that the Muso does not accept certain channels on the 5Ghz band that the Eero automatically allocates to the device.
As the Eero does not allow any band separation and/or manual channel allocation I am screwed.
Perhaps if I put another Eero near the Muso and attach it with an ethernet cable I might resolve the issue but why should I have to fork out more money for the poorly designed network element of the Muso? I might have to reintroduce the TP Link or just send the Muso back for a refund.
Thanks to all for the contributions and comments.