I have tried- just to test it- to switch to one single band out of the two available (2.4 GHz and 5 GHz)

Initially when performing the merge I got an error message about an unidentifiable error but it still merges the bands successfully.

However, the button switch that indicates that the Smart Connect is active, it's actually off but the option is still on.

I cannot now reverse the choice back to the 2 separated bands and I don't know what to do.

Any suggestions?