Strokes automatically change into shapes

It happens when I use the shortcut Shift+X to switch between stroke to fill colors.

I use it often to edit gradients since sometimes the gradient position handle doesn't appear for strokes.

Ai is v27.0

using MacBook pro,

files located locally.

happens on all files, new ones, old ones..

Does this happen when you open files? Or while working in a file?

If when opening files:

You created the files with the same version?

Where are your files located?

Exactly how do you save your files?

I haven't seen a report of strokes converting to fills on their own. Do you notice it after a particular set of steps?

You could try the following:

• Make sure Illustrator is up to date.
• Restart Illustrator and/or your computer. 
• Reset Illustrator's preferences.

If you're still having trouble, you can report it on the Illustrator Uservoice page:

• https://illustrator.uservoice.com/