A source at Montefiore Medical Center in the Bronx said the hospital has canceled recent vaccination appointments, but hasn’t offered staff a reason for doing so. An official there said there are no supply issues.

The supply snafu was the latest in a string of vaccination setbacks, highlighted by confusion over eligibility, locations and an online registration portal more frustrating to use than the unemployment website overrun by seekers of jobless benefits.

Among the most frustrated are elderly New Yorkers, many of whom have had trouble getting a shot despite being Phase 1 eligible.

“To even get an appointment for the vaccine, New Yorkers must navigate multiple buggy and complex systems,” City Comptroller Scott Stringer tweeted.