Publisher 1.7.1 on Windows 10
Create a document and set the colour profile to some CMYK profile (e.g. ISO Coated v2 300% (ECI))
Add some text and set its fill colour to black CMYK 0/0/0/100
Change the colour profile of the document to another CMYK profile (e.g. PSO Uncoated v3 (FOGRA52))
Now the black has changed to some mix
Undo the changes to the document settings
Expected: The black is now 0/0/0/100 again
Actual: The black is still a mix (haven't compared the exact values, anything is wrong)
This isn't what I'd expect from an undo operation.
Also, this isn't exactly what I'd expect from a colour profile conversion. I have a lot of work now to prepare a document for printing that should be converted to another profile, or they do it themselves (which may result in mix black again which is probably bad for text).