FrameMaker 11 in Win 10 Environment-Avenir Black and Black Oblique fonts not rendering correctly

I posted this on the Adobe FrameMaker Forum, and have not been able to get the issue resolved, so I thought that I would try here.

I am working in Structured FrameMaker 11, version 11.0/0/380 in a Windows environment.

I'm encountering issues with the bold and bold+italics versions of the Avenir LT Std 65 Medium font not rendering when I attempt to apply them to text by using the paragraph designer. In the FM font menu, the Avenir fonts list like this:
Avenir LT Std 35 Light

Avenir LT Std 45 Book

Avenir LT Std 55 Roman

Avenir LT Std 65 Medium

As I understand it, the Avenir 95 Black font is the equivalent of the Avenir Medium when bolded. The Avenir 95 Black Italics is the equivalent of Avenir Medium when bolded and italicized.

In the paragraph designer, when I select the Avenir 65 Medium font, the only available choice that I have under 'Weight' is 'Bold'. I do not see 'Regular' as an option. When I select 'Bold' and click the Apply button, the bold weight (Avenir 95 Black font) is not being applied. I can't apply the bold-italicized version either (Avenir 95 Black Italics).

It was suggested that I check the Weightings list in the FrameMaker maker.ini file and add the following entries, if they are not currently there:
Black 400
ExtraBlack 800

I added it and it did not resolve the issue.

If I remove the AvenirLTStd-Medium.otf and AvenirLTStd-MediumOblique.otf from the C:\Windows\Fonts, the Avenir Black fonts apply to the text, but the Avenir Medium is not available. There appears to be an issue between the Avenir Medium fonts and the Avenir Black fonts.

Any ideas as to how this font problem can be resolved?

Would it help if we purchased the latest version of the Avenir font family and install it?