Hi, I know this is a year late, but I was having a similar issue with tons of file changes each time I loaded the workspace.
What I found was that all the files in certain folders were not being ignored by plastic (I had moved some files from a local Unity project that likely replaced files in the repo).
For anyone in the future, look into "ignore.conf" and make sure that the files and foldernames in that file are set to private in plastic. Alternatively, add them to the ignore.conf and make them private (as of ver 11.0.16.8153 you can do this by right click deleting the file in the workspace viewer but selecting the option "Do not delete from disk").
