The reason you were seeing a change in the network is not due to separate networks, but how the mesh network functions. Both the 2.4GHz and 5GHz bands will be running at the same time, but due to how each band might vary in the distance it can reach, you might sometimes be connected to one or the other at different times. The mesh network will always select which band is going to be best for your situation and device.
If you have any other questions, please let me know.
It looks like we have this one answered and resolved. I'm going to go ahead and close up the thread. If anyone has anything more to add or needs more help, please feel free to open up a new discussion.