RAK7249 RADIO BUSY

Hello, help me please! I have gateway RAK7249 8ch and 2 rak3172 module.
The gateway reports a “RADIO BUSY” error when two end devices are transmitting messages (or trying to join the network) at the same time, even if the devices use different channels to transmit.
How can this problem be solved?


Long time intervals between sending messages I can’t use.

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