I play MCPE on Just5 Blaster. So about the bug. When youre next to button its shows when youre in stone block and you suffoticate*.
*Cant spell that word sorry.
- According to private issue MCPE-14909, it affects leaf blocks too.
- According to [Minecraft] Mega_Spud (Jay Wells), it also affects pressure plates on top of a fence. See the screenshot below.