Villagers not growing up

Put the summary of the bug you're having here

Villagers to eventually grow from baby to adult
I almost lost all my villagers in a rather huge village I had been working on to make it secure and safe. When I noticed this event happening I created a large room that was made from Acacia Wood and Glass Panes. The building was only two high inside which is just enough room to have adults or children villagers to move around in. I trapped my last 2 remaining kids and adults in this room and added a lot of doors on top of this building to try and induce mating to make more villagers. I even threw in bread to the villagers inside. This did create a lot more villager kids, however none of them ever grew up into adults. Many days and nights have gone by in fact enough days have gone by now that I know they should be grown but have not. I finished my securement of the town adding a wall, lights, better housing (with doors and beds etc), Eventually I even lost the two adults, which left me only the non-growing kids. I have since let out almost all the kids into the town to explore, save for 6 in case this happens again. The kids have been out in town now for many more days and nights and I have been giving them seeds, bread, wheat, carrots, potatoes, beetroots and beetroot seeds.

My baby villagers never want to grow up
They roam and roam my city never growing into an adult

Steps to Reproduce:
1. Not sure how to reproduce except having only 4 villagers (2 adults 2 kids)
2. Trap them in a large say 30x30 room that is 2 high inside
3. Add a lot of doors to the top of the room on it's roof
4. Hope that they reproduce and see if they do indeed not grow
5. Let them out and see if they also stay kids outside in town