Data is not adjusted for splits despite adjustment="split" flag

I am getting unadjusted values despite using the adjustment=split option.

df = alpaca_api.get_bars(
                ["RMBL"],
                TimeFrame(1, TimeFrameUnit.Day),
                "2020-05-15",
                "2020-06-30",
                adjustment="split",
            ).df

As you see the split happened on the 2020-05-20, but is not adjusted, which renders my ML model useless:

Screenshot 2021-12-19 at 09.45.52