The left is generally extremely sceptical to UBI, as its main proponents tend to be classically liberal groups (so not "US liberal") pushing it as a means to contain and limit welfare systems by dropping welfare programs in favour of a general, low UBI.

The more leftist position ever since the days of Marx has been that "right rather than being equal would have to be unqueal" to be equitable given that people have different needs, to paraphrase from Critique of the Gotha Program - UBI is in direct contradiction to socialist ideals of fairness.

The people I see pushing UBI, on the contrary, usually seems motivated either by the classically liberal position of using it to minimise the state, or driven by a fear of threats to the stability of capitalism. Saving capitalism from perceived threats to itself isn't a particularly leftist position.