How to fix "ValueError: operands could not be broadcast together with shapes (809,) (2,)" when using datetime widget for panel plot?

Question

I am trying to use a DateRange slider from panel to create interactive plots.

The year slider:

yearSlider2 = pn.widgets.DateRangeSlider(
    name='Date Range Slider',
    start=dt.datetime(1950, 1, 1), end=dt.datetime(2023, 1, 1),
    value=(dt.datetime(1990, 1, 1), dt.datetime(2018, 1, 1)),
    step=24*3600*2*1000
)

The plot:

val_vs_market_scatterplot_pipeline = (
    idf[
        (idf.DATE <=yearSlider2) &
        (~ (idf.MARKET.isin(markets)))
    ]
    .groupby(['MARKET', 'DATE'])[yaxisval].mean()
    .to_frame()
    .reset_index()
    .sort_values(by='VALUATION')  
    .reset_index(drop=True)
)

And the error message:

ValueError: operands could not be broadcast together with shapes (809,) (2,)