Did Jet Blue/Silver code share for our trip. IAD-SJU-EIS and EIS-SJU-IAD. Both Silver connections were on time.

However, the Silver boarding passes created by Jet blue when we checked in on the way down did not work and visa versa,
the Jet blue boarding passes create by Silver on the way back did not work.
Just remember to get the passes reissued at the connecting airport.