Quantstats utils.make_index() TypeError: unsupported operand type(s) for +: 'float' and 'str'

While trying to use Quantstats utils.make_index() I am getting a TypeError: unsupported operand type(s) for +: 'float' and 'str' message. This is my code that caused the error:

`import quantstats as qsqs.extend_pandas()

IAC = {"SPY": 1.3, "AGG": -.3}

portfolio = qs.utils.make_index(IAC)`

I even tested with other ticker combinations and directly entering the ticker and weights in make_index and the error repeats in the same way. I also tested in previous versions and the error repeats again. Does anyone know if there is an error in the package or is it my code?