Per the relevant NYT article it seems like the Dems are willing to push the vote to extend until next year after the midterms, when they feel they will gain seats & be able to pass

[T]he package omits the Democrats’ central demand in the shutdown fight: an extension of federal health insurance tax credits that are slated to expire at the end of the year. […] Some Senate Democrats pointed to their party’s wins as a sign that voters supported their fight to extend the health coverage subsidies, and urged leaders to dig in. But others were wary of prolonging a shutdown that has already had painful consequences, and were searching for a compromise that would allow them to end the crisis.