geopandas known intersection returns False

You do not select one polygon but one row of the GeoDataFrame. Therefore you are using an intersects on a Series, not a Polygon. As shown in the documentation, geopandas aligns those series and do row-wise 1:1 operation. You need to pass a shapely.geometry if you want to check all rows against a single geometry.

# this is shapely.geometry.Polygon
geom = Dataset1.loc[Dataset1['ID'] == 15000, 'geometry'].iloc[0]

Dataset2.intersects(geom)