Why does my MacBook flash the screen when receiving emails in Outlook or messages in Teams?

A user in my organization is facing issue that the MacBook is showing the same animation as it does (flashing of the screen) when its taking a screenshot whenever they are receiving a mail in MS Outlook or getting a message in MS Teams. we have checked and confirmed that the screenshots are not taken but just the animation (flashing of the screen)is being run. We have disabled the notification for these applications as a workaround and it stopped the flashing of the screen. But is there a solution for this issue.

[Re-Titled by Moderator]