Orbi Auto Channel Selection (2.4GHz)

Does anyone have any insides how the 2.4GHz band auto channel selections works?

How does the Orbi determine the optimal channel? Does only the router or both router+satellite scan for best/free channels in the surroundings?

I’m asking since the auto channel selection doesn’t work well here with a lot of neighbours. On auto setting the Orbi always selects the channel 13 (40MHz). On this channel (client connected to Orbi’s 2.4GHz band) I can hardly get any throughput (1-2Mbit/s). I manually set the 2.4GHz band to channel 1, which works best/ok (considering the interferences from my neighbours). 

I’m fine with manually analyzing the channels and selecting one, yet the auto channel selection feature is quite disappointing for a „plug ’n’ play device“ like the Orbi wants to be. Especially selecting 40MHz wide channels in such a crowded 2.4GHz band is not understandable to me...