Mob AI behaves differently after using tick freeze.

Goal based Mob AI ticks some Goals only every 2 ticks. This is decided by using the Minecraft server's tick counter. During tick freeze, the frozen ticks modify this counter. Freezing and unfreezing modifies the counter, effectively randomizing whether the next Mob AI tick will try to tick all Goals, or only important Goals.

This breaks contraptions which are dependent on specific mob ai behaviors. For example the contraption shown here: https://youtu.be/F9WopDkCgCs?feature=shared&t=269 (world download in video description if needed)