When continuously digging dirt using the shovel, the shovel disappears from the hand and the shovel icon starts to flicker and does not dig anymore. After a couple of seconds of releasing the mouse button the flicker stops and the shovel reappears in the hand.
This already happened for three times in about one hour of gameplay and only after receiving the update today on a survival game in which the Experimental Gameplay is not enabled.
The shovel being used is a diamond one with:
Silk Touch I
Unbreaking III
Efficiency IV
Mending I