I can't change coordinator module in XBee S2 network (API mode)

I have network with one coordinator and many routers in API mode. All modules are set to the same PAN id (431) and everything works great. Coordinator is connected to PC and routers are standalone devices.

But if I take another S2 module and configure it exactly the same as coordinator (with all the same settings), it cannot discover other modules in network or send data to them (tested with X-CTU). The module works if configured as router.

I need to have backup coordinator module in case something goes wrong but it’s just not working.

there can only be one coordinator on a zigbee network. You are in effect creating a whole second network. Coordinators do not work together.

Yes, I know that. But that’s not the problem.

I need to have another coordinator module as a backup if something happens to the real coordinator (for example, I accidentaly step on it :)). It will not be turned on when the first coordinator is on.