A person receiving UBI who lived in San Francisco proper and got free housing would essentially get 5x - 10x effective benefit than someone living where rent is $500 / month. Cue the inevitable conflicts over who gets to live where, and caps on what level of UBI will be provided.
But conversely, if the UBI benefit were a fixed monetary amount, then you'd be consigning UBI beneficiaries to never live in an expensive area where urban professionals work, so you would create a geographical and social divide where UBI recipients are consigned to live in low-income slums.
I don't see any way to resolve these dilemmas that would make all people happy, unfortunately.