Squids do not maintain horizontal inertia on land and do not maintain vertical inertia in water. This issue is server-side, so it causes massive desync, even in singleplayer worlds.

Steps to reproduce:

• Hit squids with high-knockback attacks
• Push squids on low friction surfaces
• Drop squids into the water from a very high place
• Put squids in bubble columns

Here's a video demonstrating the issues: https://youtu.be/9-COs5CHL18