Ghost or sticky width settings between variables

Hello.

Is this a bug?

I have a set of variables to control layout in Desktop, Tablet and Mobile breakpoints.

If I apply a variable width to a frame and switch it back to Fill container, it reverts back to the variable width when I switch to the other breakpoints. I’m constant re-applying Fill container.

Does Figma somehow remember the previous setting and revert back to it? Infuriating.

Or is it me?

Thanks,
Will