The problem with a UBI is that it is (in theory) supposed to replace the multitude of payments through various government social programs with a single check or debit card given to every recipient every month, at which point the various government agencies that administer housing, food stamps, etc., can be shut down. Government bureaucracies never shutter themselves voluntarily, and it won't happen with a UBI, either.
The UBI operates under the assumption that everyone manages money in a rational manner, which is completely at odds with actual experience. Many people will take their UBI and immediately spend it on drugs, alcohol, gambling, or bling, while ignoring the monthly rent, the electric bill, buying groceries for the children, etc. Others will be cheated out of their money by criminals or even other family members. So do we let those families starve or get evicted because the heads of household are incapable of managing money for themselves or their dependents?
Of course not. Those people will need to be helped (sarcasm intended). So the various government agencies will continue to expand and spend even more money on housing, food, medical care, etc. The UBI won't even make a dent in entitlement budgets. Instead, it will become "free money" to be squandered on a thousand other things besides basic human needs.
Anyone who doesn't think it won't happen need only look at inner city schools in the U.S. In theory, every child should be getting meals at home thanks to government SNAP benefits to their parents or guardians. In practice, schools give many kids a free breakfast and lunch every school day, and even give them food bags to take home for the weekend, because Mom or Dad can't be bothered to buy food for the kids with the SNAP money. Where does the money go? No one knows or even attempts to find out. They just give the kids free food and cross their fingers.
The UBI will not change human nature. It will instead become one of the biggest entitlement boondoggles in the history of civilization.