The device does not utilize all available channels in an optimized fashion while attempting to join the network.

[QINLIMIN]

hi, my end-device join mode is otaa, ADR is on, freq plan is US915, loramac is 1.0.4, and LORAWAN_CHANNEL_MASK config as "000000FFFFFFFFFFFFFFFFFF".

For the specific channels, according to the RP002-1.0.3 LoRaWAN Regional Parameters, Section 2.5.2, “the end-device SHALL transmit the Join request message on random 125 kHz channels amongst the 64 125 kHz channels defined using DR0 and on 500 kHz channels amongst the 8 500 kHz channels defined using DR4. The end-device SHALL change channels for every transmission. For rapid network acquisition in mixed gateway channel plan environments, the device SHOULD follow a random channel selection sequence which efficiently probes the octet groups of eight 125 kHz channels followed by probing one 500 kHz channel each pass. Each consecutive pass SHOULD NOT select a channel that was used in a previous pass, until a Join-request is transmitted on every channel, after which the entire process can restart."

And, more specifically, the example listed:

• First pass: Random channel from [0-7], followed by [8-15]… [56-63], then 64
• Second pass: Random channel from [0-7], followed by [8-15]… [56-63], then 65
• Last pass: Random channel from [0-7], followed by [8-15]… [56-63], then 71

But, my end device sends Join Requests on repeating channels before all channels are utilized. Below,the device reuses channel 0 (902.3 MHz) twice consecutively:

Please help to give some idea, thank you.