I need to preface all of this with: This is a work machine and we have required processes and deliverable file types. I cannot just "save as a pdf instead.” I must keep these as .ai files and I am not allowed to update my operating system nor Adobe apps until updates are pushed by IT. There are also some files I cannot share with you since they are proprietary. Since recording my screen, that file no longer has the phantom object issue-- so you're not going to see what I was seeing at the time I recorded it.
I have tried saving without pdf compatibility to see if that fixed it— but that created an entirely new issue when previewed in Finder. Attached is one of the .ai files I used to test— saved as pdf so that this website lets me upload it. Of course, saving as pdf fixes the issue, so I’m not sure how that’s helpful for troubleshooting.
Below are screenshots of what the file looks like in my Finder/Preview. Another is what the file is supposed to look like. (Note that the color is incorrect on the one with pdf compatibility. A work-around we’ve figured out to get the color to appear correct is to hide the visibility of all layers and ALL the objects/groups within those layers. Which is super annoying if I ever need to go back and amend the file.) Also below are screenshots of my Illustrator version and MacOS.







