Mobs/Entities not despawning!

So last week I created a new survival world in the new 1.11.0.9 beta on my xbox one, and I've noticed that mobs and entities, specifically dropped items and xp orbs. I first noticed it when I went to my blaze farm and all the blazes (probably about 15 or 20) were still there! This was after I had went back to the overworld for many nights AND exited and saved multiple times. Since then, I've noticed that sometimes dropped items will last way past 5 minutes and past exit and saves. Xp orbs stay as well. I have killed mobs hundreds of blocks away from my house and even after many minecraft days have passed I can go back and collect the experience.

 I'm pretty sure that this bug is affecting the spawning of hostile mobs on the surface as well because I try to go out at night to get ender pearls and I'll be lucky if I see even a single zombie! Please read this so I can go to the end!