I ran into a similar issue. Not sure why, but for some reason the last label on the 2nd slider won’t show. It doesn’t like the decimal value (201817.0). It isn’t clear to me how this is different than the 7.65 label in the first slider.

html.Div(dcc.RangeSlider(
min=0,
max=10,
step=None,
marks={
0: '0 °F',
3: '3 °F',
5: '5 °F',
7.65: '7.65 °F',
10: '10 °F'
},
value=[0,5]
)),
html.Div(dcc.RangeSlider(
min=201813,
max=201817,
step=None,
marks={'201813': '201813',
201814: '201814',
201815: '201815',
201816: '201816.0',
201817.0: '201817.0'},
value=[201813,201817]
))