Keep getting wrong password error message

Most Netgear routers have a limit of 32 clients per frequency band (i.e. 32 for 2.4 GHz and 32 for 5 GHz).  The guest network uses either the 2.4 GHz, 5 GHz or both.

 

These home market routers don't have no effective way to prioritize bandwidth to non-guest devices.  You'll need business-class networking equipment to accomplish that.