“Popping and clipping sounds” points to a clock issue. You need to pick one console that will be the “master” clock for the entire system.
On the “master” console:
Set the internal console clock to “Internal”
In Dante Controller, set up this master console’s Dante card to “Enable Sync to Ext”. This tells the Dante card to look outside of the Dante system (ie look at the console) for it’s clock settings.
In Dante Controller, set up this master console’s Dante card to be “Preferred Master”
On the second “slave” console:
Set the internal console clock to “I/O Card” and choose the Dante card slot
In Dante Controller, set up this slave console’s Dante card to “Ext sync off”.
In Dante Controller, set up this slave console’s Dante card to be “Preferred Master Off”
This should fix the popping and clicking sounds.