Pausing while breaking blocks

New game in large biomes. I experienced the suffocation bug on creation.

When breaking blocks (but before they break) the game will pause. This appears to get more frequent and led to a white screen and unresponsive game. I had to ctrl/alt/del to get the mouse control back. I repeated the behavior in a new session of the same saved game. I forced a crash after the second occurrence of the behavior. See attached.