As a critic of UBI, that's not what I expect at all. I expect all of these tests to have wonderful outcomes where people who get their share are able to make good choices, invest in their future, and become better off than their neighbors. I expect that this will always be the case for any test done with UBI, because I understand that these tests are modelling a situation fundamentally different from what would happen if the basic income granted were actually universal - publicly known and guaranteed by the government.
In the test, wealth is coming from outside the system to individual economic agents within it. Of course those agents become better off than others who are not granted this wealth. But a government does not create wealth by fiat; they take it through taxation to distribute and spend according to priorities (ideally) set through popular decisions. They cannot make the group as a whole objectively richer - schemes to try anyway through blanket money printing result in unwanted inflation.
What I would actually expect to happen, should UBI somehow be implemented, is an immediate capture of the extra wealth by the capital-owning class. It won't be used by the currently homeless to afford homes, because the day after it's announced, rent prices will shoot up by about 70% of the amount. You will still need a job to afford a place to live. Likewise all basic goods; food, fuel, education, all their prices will rise to consume the greater discretionary income that people have. You can't win the Red Queen's race. Speeding everyone up the same amount doesn't change their relative positioning.
True, it would make debts suddenly worth a lot less. The government could also choose to do so by fiat, but they are very unlikely to. It's not difficult to imagine why.
Worse, the expense of doing this - it would cost more than the federal budget in the USA, assuming everyone is given a modest $2,000 monthly - means that taxes would have to rise, making it harder for people to actually rise in economic status through productive labor. I can see, assuming that this state of being continues long-term (which I personally doubt it would), a permanent divide appearing in the economic strata in the population over this, between people lucky enough to own property at the time the UBI was implemented and those who weren't.
Despite the woe about wealth mobility that already exists (at the moment, people in the bottom quintile economically have a 40-60% chance to escape it[0]), it can always get worse. Ideas to fix it should not be judged based solely on their intent. UBI is a solution that is conceptually simple (there are poor people? just give them money!), politically easy (who doesn't like free money?), and absolutely rife with harmful second order effects. People change their behavior according to incentives - this is true both of the poor who historically have been the targeted beneficiaries of UBI tests, and the landlords and corporations that will change their policies to optimally harvest a new bounty if these policies were ever implemented more widely.
[0]: https://www.brookings.edu/articles/stuck-on-the-ladder-wealt...