Call Handling and Forwarding

We have desktop phones as well as cell phones listed on our Ring Central User Settings. The desk phones are always set to ring, and we have one cell phone selected at a time (This is all in 'Settings - Call forwarding and handling'. Randomly during the day, RingCentral will automatically group and turn on the rest of the cell phone users so everyone gets phone calls. Is there a way to prevent this from happening?