Thank you for reporting a bug to Unity.
After reviewing the behavior, we've confirmed it aligns with the current design and intended use of the feature. We understand this may differ from your expectations or workflow.
We have found a potential fix on the project side which is to rename FixedUpdate to LateUpdate (https://docs.unity3d.com/6000.5/Documentation/ScriptReference/MonoBehaviour.LateUpdate.html) in InputController.cs, since the value for camZ (which is used in calculating movement for the fish) differs between Update and FixedUpdate when running the project on MacEditor and Web. This difference in camZ value does not occur with using LateUpdate.
We will close this case as 'As Designed.' If you have feedback on how the feature could better meet your needs, please let us know - we value your input and consider it in future improvements. If you would like to reopen the case, please provide a minimal repro of the specific issue.