When trying to show a PowerPoint presentation the mouse pointer disappears so you can't control your slide show.
This can be a real issue if you are trying to screen share a slide show via Teams or Zoom and you need to use the mouse to manually advance slides or start/stop music.
Things to Try:
1)Whilst the slide show is running right mouse click on a slide and chose Pointer Options > Arrow Options > Visible
The pointer should now not disappear during this presentation, however this option will reset next time you present the slide show and unfortunately cannot be set permanently.
2)Try using keyboard shortcuts to control you slide show rather than the mouse - for example ALT + P to pause music, S to stop/start slide show.
More keyboard shortcuts can be found here
3)View slide show without using full screen.
To do this click Set Up Slide Show on the Slide Show ribbon page and choose "Browsed by an individual (window)" and click OK