One is Alaska’s Permanent Fund. Look at their gini index among all 50 states since the fund launched.
https://onlinelibrary.wiley.com/doi/10.1002/pop4.398
And the conclusions are similar. Better health. Lower inequality
The other is Manitoba’s MINCOME experiment, they randomly selected people — it was doing very well but somehow the powers that be pulled the plug: https://humanrights.ca/story/manitobas-mincome-experiment
If $150 a month can make people’s lives better, in a state that doen’t issue its own currency, imagine what phasing in a UBI for everyone in USA can do, gradually and increasing. And that’s the point.
USA will have to print money anyway to service their sovereign debt. So may as well give it out as a UBI over 40 years first, then tax it and pay the treasury holders. Think about it!
Either it is never universal, and / or participants know that it isn't going to last long (limited duration study) so they have different motivations than someone who will actually receive UBI.
Every study basically has the same (obvious and not useful) conclusion: people like getting money. Any conclusion beyond that (specific to UBI) isn't supported.