Illustrator suddenly changing blurred/masked objects to images

[RockyRakoon]

For years I have used a technique where I create a vector shape and give it the Gaussian Blur effect, then creat a mask which crops out some of the blurred vector object.  I could then go back...even years later...and select the vector shape within the clipping-masked object and modify its shape as required.

But something has just changed in Illustrator (I'm using version 27.0.  I create the blurred-then-clipped object as before, but after saving and quitting the program something is now very different.  Opening up the file again, I can sstill see the clipped masked object, but withiing the clipping mask there is no longer the original vector object.  What's withing the clipping mask is an image based on the bounding box...meaning that I can no longer modify the original vector object that was created.

Attached image shows the problem in the layers pallete.  You see a clip group consisting of a blurred path and a rectangle.  That is how this was originally created.  Below it you see a clip group consisting of a rectangle and a group.  After saving and relaunching, the blurred object is no longer a path but an image withing the original's bounding box.

What is causing this...a major issue for me.

[Doug A Roberts]

Are you saving it as an AI file or PDF?

I can't replicate this in version 27 on Windows. Can you share an example file?

[RockyRakoon]

well, now that's weird...It's not doing this with a new drawing, so there must be some sort of issue with the file I'm experiencing this with...  I must have some switch thrown in preferences that is doing this but I can't figure out what that might  be....

[Monika Gause]

So this is an old file?

You opened it and could edit it and then just saved it?

You might have been hit by this:  https://www.vektorgarten.de/illustrator-legacy-file-warning.html

[RockyRakoon]

That has to be it...I have reset my warnings but now have a whole lot of work to fix...

Thank you!