Minis show up in groups automatically in Airplay 2

[Paulinator2]

My client has 8 Minis that work great, but when he opens up the Airplay 2 device list, they show up as a group of 5 and a group of 3, automatically, every time, while other devices like Apple Speakers are separate from the groups. I've checked the WiiM app and they don't appear to be grouped or connected to each other in any way. Does anyone have a solution to make them appear separately? It's not a huge issue but he is a fairly old guy and would prefer as much simplicity as possible for him and his wife. Thanks in advance.