"Save as..." doesn't work properly

Sorry, sometimes ago I asked something similar, but I can't finde the topic...

Anyway: from Version 8, the command "Save as" doesn't work properly, especially saving from a format to another.

Until version 7 it worked, now (from version 😎 it seems to work as a "Save a copy".

For example,  if I have a .mif file, and save it as .fm file, changing only file extension (Goofy.mif --> Goofy.fm), my open file still remains the same .mif file (Goofy.mif), while a .fm copy, called Goofy.fm is saved  properly.

So, if I want to work on my new file I have to close the mif file, and then reopen the .fm file.

It seems a bug to me, because if I save (not export, or save a copy) a file, in any programs, with a different name, I expect that my open file will change name (as it did until version 7 of FM).