I use Teststand 2020 (184.108.40.206158 64bit) I think thats the problem in XML Help. When I insert .Net module dll and method on this dll has parameter with enum, xml help is not visible on parameters of this method. If method has parameters with (bool, int, string etc.) XML help is OK. I noticed that in Teststand the enum parameter is displayed with + symbol but on xml file that is . symbol so I try to edit xml file which visual studio generate automatic and all . symbol next to enum parameter I rewrite to + and xml help going OK. I think that is issue on teststand because + symbol is not valid symbol on xml file for this situation.
I write example method in C# with enum parameter and attach screen of C# code, teststand and also xml.
Then I edit XML and . symbol before enum I reedit to + symbol and XMLHelp working OK (look to attached files)
Best regards Igor
It looks like a bug or undocumented limitation to me. I would suggest opening a service request. You can link your post there.