The R-179 train cars on the A, C, and J lines are causing a lot of operation issues in the past 2 years.

https://www.ny1.com/nyc/all-boroughs/news/2021/03/05/mta-s-troubled-train-cars-overran-stations-in-queens–operators-say-they-are-notorious

I have always been proud that the MTA’s train cars are designed by Kawasaki Rail Car, a major Japanese heavy industry manufacturer, so I was shocked when I heard this news. But, it turned out that the type R-179 happened to be the only MTA’s New Technology Trains car that was NOT designed by Kawasaki Rail Car.

https://en.wikipedia.org/wiki/New_York_City_Subway#cite_ref-176