This is a midly frustrating issue which happens with teams but used to work fine with Skype.
I can share specific applications with other users but if I share my screen while on remote desktop the viewers can only see a black screen.
It would be really good to get this fixed - hope this is the right place to get some advice or request a bug report?!
Hello @DaveH65 Our Uservoice feedback forum is the place to report bugs (or look up if something similar has been reported), make feature suggestions, etc.