"The Jitterbug (Remix)" was a song AJR played on tour in 2018. The song is not known to have ever been released. The song also contains spokstep.
A recording of the song can be found here: https://www.youtube.com/watch?v=HtsE1J-Frj8&list=PL3b-FK09iBPITX4-JW8Btan-eK4devwGv&index=3