Screaming and crying at bedtime

My 4 month old started crying and screaming when she enters her nursery at night (literally the second we cross into the door). During the day she is fine in the nursery. This has been going on for 5 nights straight. We had established an evening routing that was going well but something flipped. She now will cry and scream for 2-3 hours before passing out. Nothing helps. Not breast feeding, not changing the routine. We can’t find anything that works. Has anyone else experienced this and if so, how did you solve it?