2nd player got stuck breaking blocks when 1st player opened chat

The bug:
When the first player is opening the chat window while the second player is breaking blocks, the 2nd player gets stuck swinging with out touching the buttons.
What I expected:
For the chat window to open and work as intended.
What happened:
The second player was stuck breaking blocks.
To recreate:
Again, haven't been able to recreate the issue but I'm sure it will happen again with enough determination.
Solution or Temp fix:
Changing hot bar selection back and forth