villager linking issues

We have been having trouble with villagers linking to beds upwards of 400 blocks away from the beds or work stations we even tried sending them into the nether and they still link with work stations and beds placed in the over world. We have also had trouble with random villagers just despawning we breed more villiagers go through all the effort of linking them all with the beds and work stations properly then they just disappear a couple hours or so later they are in enclosed mob proof capsules and they still despawn so they can't be getting killed by mobs. 

we use the villagers in a 20 man farm for wheat potatoes etc the farm has run perfectly for months and months and now we are having loads of trouble with villagers delinking and re linking to the wrong beds/workstations, the centre of the village constantly changing and have had over 100 villagers just despawn over the last week or so. We replenish with brand new villiagers linking them 1 by 1 in the farm transporting using mine arts from a village breeder that has to be over 500 blocks away to as anything closer and they all link with beds and mess the farm up it never used to be this far our village breeder for our iron farm was only 80-100 blocks away and never had an issue. I'm pretty sure it coninsides with one of the recent patches. Our farms with villagers haven't worked correctly since.

pretty sure this is a bug hope you guys can fix it because auto villagers farms are awesome our 1 20 villager farm used to provide wheat seeds potato's carrots bread honey and honey Combe eggs Poppy's string and iron all in one farm it's worked solidly for 6months plus and now we just have weird things going on with the villagers. I searched for a related post but found nothing so I'm creating this thread hope you can help guys please fix this bug it's brutal