RATING WMP tag question

When i put 4.4 per example in the rating wmp tag, it don't save, this is happening in some albums but not in others.
it is because in m4b files it can, and other extension it cant?

I think that the field expects integer values or asterisks.

but in m4b it works:

Which program shows it like that?

i use it for export html

As this maps all to the field POPM, it is only the difference in format that determines which program it likes.
While some programs like stars, some like numbers and others like bits, there is also the format for Rating MM which accepts half values, so e.g. 4.5.
It could be that some kind of rounding mechanism hits.
And where do you see the bug if it is a custom made html export?