None of my blocks are dropping in my survival minecraft world, (PE)

I just deleted two of these tree blocks for example and nothing is dropping. I just want to play minecraft!!!! Please fix this bug!!  and I tried to see if there was an update or something or if exiting the app and going back to it would work or if undownloading it and redownloading it would help but nope. still won’t drop blocks or weapons. :/