Inkscape version 1.0.1
Windows 10.

I've got a shape where I've used fillets to round some of the corners. When I try to scale the image the fillets do not scale correctly. Is this to be expected or is this a bug?

This seems to happen when the object is shrunk to a much smaller size.

In some cases the fillets seem to disappear completelty and in others the fillet does not scale properly.

When the fillets dissapear scaling the object up again they don't re-appear.

The screen shot shows the original image and a copy that was resized down and then back up again. In this case the fillets suddently dissapear.

It's a lot harder to get the fillet scaling to go wrong completely but I will past an example if I can capture one.

I've also attached the svg file that has the issue.
 

If you are scaling path effects, it can sometimes go wrong, if you are happy with the big image and just want to scale it. 

Save a copy so you can go back if you want to. 

Select all, choose Path>Object to path, it should set the path effect as a normal path, which can be scaled okay. 

Just remember to have bounding box set in Preferences > Tools  to either visual or geometric if you are doing measurements.

Visual includes the stroke width etc, Geometric measures from the line that passes through the nodes, so ignores the path stroke.