Reproducing this requires modifying an existing script (adding new variables), assigning a value to the new variable, publishing, and having a second client grab the files from a collab Update.

When the second person downloads the update and reloads their scene automatically, they will see the new fields from the script in the inspector, but the values will be defaults ("none" for objects, "0" for int, etc.). Re-loading the scene locally fixes the issue and picks up the new values.

Making additional changes to the scene and saving them without fixing this (by reloading) will save off the default values instead of the original values.