How to undo "Experimental Feature" to stop the Alert Popup

Hello, I accidentally fat-fingered something and may have turned on some setting Ididn't intend to. 

I keep getting this experimental feature alert in the bottom right corner? How do I turn off whatever experimental feature I may have turned on?

I'm unable to track down whatever I may have triggered i the cmd+shift+a menu.

I'm on Mac

Thanks ahead of time.