Please help me to rescue my deconz network, I've tried everything

What about adding more or better router devices? will it improve the situation?

I know it’s not a common practice and often can make thing worse, but what about splitting the network in half and using 2 conbee II devices as coordinators one in each side of the network instead of one in the center of the house?
The vast majority of the sensors is located in 2 rooms and the othe rooms have only a couple of switches and window sensors devices so I can place there each conbee II…