Minecraft texture bug & Save And Quit Bug

Hello Mojang

You are reading this please fix this bug.

My phone is a Lenovo vibe k5

The texture bug happens every time I go to other screens(ex.messenger and YouTube) and back to Minecraft,and I'm tired of restarting Minecraft because of this bug

And this also happens to my friend

His phone is Galaxy 8+

 

And the save and quit bug happens every time I quit the game normally