Ugly Textures/Texture Bugs

Umm As the Summary Says Ugly Textures When I Spawn Something With Arms It's Arms Disappear By Summoning them like this /summon pillager ~ ~ ~

{NoAI:1b}

There Arms Disappear And When I Take Something From The Creative Menu some of The Items Are Discoloured And Some Of Them Are completely Invisible This Only Happens in my hand/offhand 

It's Really Disturbing and Should be Dealt With i've Had smaller Problems But This Is Big
Also The Grass Block's Top Textures Is Snowy