Hi
@Timothy Merridew,
Unfortunately not. If you come out of the Powerpoint and return to it then you will return to slide 1.
I think its a great ask and would recommend raising a uservoice here:
https://microsoftteams.uservoice.com/forums/555103-publicAs an MCT I also need to deviate away from PowerPoint time to time. A workaround is to share the desktop and then switch out: but this isn't ideal and it would be better to both switch between PowerPoint and other apps in Teams and have persistent PowerPoints if used in the presentation.
Hope this answers your question
Best, Chris