JB did the same to us. Moved our JB flight on the way home departing SJU forward by one hour cutting our layover time to get thru C and I down to 1 hr.
Too close for comfort for me.
We had too rebooked on an earlier Silver flight out of EIS. Now a 4hr+ lay over at SJU vs 2hr.
This all had to be done thru JB. Spent longer on hold than our layover!