@Laura2592 being able to add a guest to a reservation when it has already started. It's not possible at the moment so if a guest turns up with more people than is booked for your options are to cancel the booking, make a request for the additional funds (which the guest can ignore), or just suck it up & absorb the cost.
And they need to fix the bug when a guest wants to extend their stay & the new request calculation ignores any discounts or special offers that the guest has already accepted and just reverts to the base nightly price. It invariably ends up charging the guest so much more & if a host doesn't pick it up it looks like we're trying to rip off the guest, not Airbnb messing up.