Hello Microsoft,
This problem is also happening to me in all of my Office 365 apps. I use the installed apps, not the online ones. It started this week. I have to uncheck "Provide Feedback with Sound" frequently. Eventually, I give up and just mute my computer because "Provide Feedback with Sound" keeps turning back on every single time I turn it off. I have just discovered that if I uncheck the box in outlook, then go to excel and uncheck the box there, then I go back to outlook to see if the box is still unchecked and discover that it has re-checked itself the moment that I unchecked it in Excel. Please find the fix for this.
Thank you