I've tried several services since Vader's went bye-bye and they've all had issues (different on each one) with Nick Jr.
One just never played the stream, a couple buffered every 10 seconds, one would most up the UK Nick Jr with the US feed, and the latest is showing Showtime 2 on the Nick Jr feed.
Granted, there may be more channels with similar issues but I've got a 5 year old that has a severe Paw Patrol addiction.
Yeah I've run into this situation a few times with different providers - if you are in the US you could always spring for Philo $16 a month for legit Nickelodeon