2 year old random sleep change

My 2 year old has always been a great sleeper, would happily do the bedtime routine every night, we would lay him in his cot with the lights off, door shut and he would just roll over and be asleep within 5 minutes. No tears, no drama and would stay there for 13 hours. Literally overnight his sleep habits have completely changed, he is SO distraught before bedtime, is petrified all of a sudden of the door being shut, the lights being off, seems to hate his bed and being in it. Waking during the night so distressed and the same in the morning. He completely hates everything to do with his bed/going to sleep and this has come totally out of the blue. Has anyone else experienced similar? Struggling with this change massively 😩