I have make more test and I can say that 2 radios transmit simultaneous can be work in 5Ghz-onlyN. There is no problem with interference. I test with separate boards and it’s work but when I put two radios in same board it fail…
I’d suggest check your LMR cables - and separate your antennas more. the N radios are super sensitive to noise (or so we’ve found) we’ve had more than one leaky cable cause us trouble!
I suppose thats because they are highpower and stacked, in an RB4xx series at least. Let me know if you ever get this to work It could explain why we have some poor performing links shared with high power N cards