Scale in object mode not working between 0 and -1

I appended this object from another blend and when scaling it in object mode it does not behave as any of my other objects. I have no idea what I have done to change it’s behaviour - does anyone know what is going on?

(In the video I scale around the cursor on the X axis. Normally I just press s->x-> (-1) to flip it. In this case it is not working. I made a new object to show how it usually works (the cubes))

Sometimes that happens when a mesh is rotated and scaled in object mode, try applying scale and rotation (ctrl+a) and see if that helps.

Thanks for the reply. This does deal with it in as much as I can scale it, as I can in edit mode. Ideally though I wanted to keep it with the same edit mode structure (un-applied loc/rot/scale) as all the other duplicates of this object. I am finding it so strange that I cannot re-create this behaviour with any other object even if they have the same loc/rot/scale.

Could you share the .blend?