Villagers apparently not recognizing village doors and going outside village radius. I've tried to replicate the bug and results are as it follows:

First, the problem: I started playing in Survival Mode, snapshot 18w11a to be precise, and created a world with seed "ubicaritas" (in case someone wants to replicate). As soon as I found a village (coord. 805, 644), I settled in and started building houses/adding doors. Some minecraft days later, villagers started to move away (southeast) from the village center, ignoring my new door placements. I've tried to move them back by using minecarts, but to no avail: a few minutes later, they would start going southeast again. I tried to build new houses southeast (so they would not move farther). Still, that did not make them stop: they insisted on continuing their pilgrimage southeast. So I went away from this village and build my new home in another near village (coord. 1109, 725). Again, in a few minecraft days, villagers started moving away from the village center (SE again). Strange thing is that there is a big hill southeast from this second village, but they managed to climb it to the top somehow, thus moving far away from original village radius. I did build lots of houses near the village and brought them back using minecarts, but that did not stop them again.

Replications:
1. I created a new world with the same seed, but in Creative mode. I moved to the second village location and watched the village from above the well. I made sure no change in the original village was made (no doors added/removed). Some minutes later, the same thing happened. Then, I've tried to add lots of valid doors to see if they would move closer, but nothing happened. Screenshot 1 shows when I arrived in this village, while SS2 is how it was 10 minutes later.
2. I created a new world with Superflat terrain. As soon as I found a village (coord. 2373, -1242), villagers started migrating south-southeast. No changes on houses were made. SS3 shows this village as soon as I found it; SS4 is what happened 10 minutes later. Tried to add lots of valid doors onto this Creative world village, thus shifting village center. Didn't work either.
3. Tried to create a new village with 1.12.2 version, same seed (completely different world, though). No such behaviour was observed.

Thanks for your time. I hope this get fixed.