this happened to us too. we updated from 1.13.2 to 1.14 and as a mod on here told me to fix it we had to optimize world and clear cache from a world that hadn't been opened in any 1.14 snapshots which we did but we still have this problem, and as the poster said portals seem to affect this.
this happened to us too. we updated from 1.13.2 to 1.14 and as a mod on here told me to fix it we had to optimize world and clear cache from a world that hadn't been opened in any 1.14 snapshots which we did but we still have this problem, and as the poster said portals seem to affect this.