I've had this happen in 3 seperate 1.14 worlds. Everytime I build an iron golem farm, then save and close the world, then reload them, upon the time being set to 1, the first day of minecraft i get essentially no ig spawning. then the next day it starts to slowly increase. by the 4th day the farm is back up at full capacity. I have a farm generating 1000-1200 ingots per hour, and upon loading the farm i get 10-20 ingots on the first minecraft day.