Mobs spawning and despawning right next to me

So I've been dealing with this problem since the nether update. First happened when I trapped a chicken in a hole. Turned around and walked a couple blocks away and came back. It was gone. Found another. Same thing happened. Now I have to constantly breed my animals to keep myself from having none at all because they despawn as soon as I turn my back it seems. Mobs also spawn in groups of 3 and explode out of eachother and start roaming around. And I see this every time I leave my house. Hostile and passive. I've seen 3 zombie villagers spawn literally 6 blocks away and then explode out and hunt me down. Same with a pillager group. I feel like I shouldn't be able to see 3 mobs spawn inside eachother so close to me like that. Even if my house has torches everywhere mobs still spawn inside. I can leave my animals for 2 seconds and come back and them be gone accept like 2 chickens. Tamed animals even with name tags despawn as well as villagers. It's been an issue for a long time now and would love to see it fixed