Additional meeting and call-related features and issues within Microsoft Teams for business
The work-around is to share the desktop window and ‘play’ keynote there. It helps to have Keynote on another device (ipad or iphone) as this lets you use the second device to control the presentation (advance slides, see upcoming slides, see presenter notes, etc.). This ‘workaround’ is entirely courtesy of Apple. Microsoft (especially TEAMS) sucks!