Red screen recording powerpoint

Hello,

I have office 2019. I work with MAC. (high sierra)

I have some problems with powerpoint 2019.

Problem 1) When I want to recording (when I talk)  the slide from my powerpoint I see only a red screen.

Problem 2) When I talk and want to recording, there is sometimes no sound of the slides.

An other question: can I have a button on my powerpoint before screen recording. (make A film of an anther site)

My language is Dutch. Can you answer in Dutch please?

Greetz

Marieke Thierens