YEs--I have NEVER set custom pricing (I would have to learn how!) and yet one of my guests was given six out of ten nights at a 35% discount below my lowest nightly price (I did not authorize or initiate) Can't seem to get a straight answer from airbnb help center. They first told me it was because of my 10% weekly discount--which it is not. They then said it might be a bug and later said it was not. They apologized and said guests had already left and that the guests had been extended a custom price (insinuating that I extended it)
They wanted me to ask guests to pay the difference. Not fair to the guest! Both guest and host acted in good faith. Seems to me air bnb owes the difference to host. (me)