This issue is crucial, finding monsters in overworld feels like I'm playing in easy-peaceful difficulty (I'm on hard mode)
What makes the trade UI keep closing is because you maybe destroy their worksites, or the villager can't find their worksites. Try to place a worksites that are match to their roles. This issues is happening to me when I try to trade something with a farmer (that already has trade xp) and it suddenly close due their worksite is destroyed, so then i place it again and it works as usual.
So it's fixed in 1.14.3 pre release 1. but the spawn rate is too small for me in my own world
What makes the trade UI keep closing is because you maybe destroy their worksites, or the villager can't find their worksites I think. Try to place a worksites that are match to their roles. This issues is happening to me when I try to trade something with a farmer (that already has trade xp) and it suddenly close due their worksite is destroyed, so then i place it again and it works as usual.