Ok so I'm constantly getting 30fps dip and it stays for few mins at any world that I have played. Been getting this issues since 1.9.0 and I just thought that https://bugs.mojang.com/browse/MCPE-41479 would fix this issue.
I just assumed it would be fix in further newer versions.
I'm using a game cartridge not digital.

Edit: This bug effects Docked and Undocked. And while constantly having 30fps, I decided press the home button and go back. Instead, it took few seconds to go back to the game.