This happens to me all the same.
So I usually work in a multi-file set up for larger projects to allow multiple users to work on the same project.
I would usually do one floor plan and copy and then copy and paste it as the starting point for other files.
However after the files are all been edited, the size of the file stays the same (massive)
Any ideas? Thanks.
Kind regards,
Henry
Do the files start out small it could be something in your seed file.