Using 8.1.44, I have a tab container using classic menu type and I have what seems like a white rectangle behind my active tab I can’t seem to get rid of
If I change the color of my active tab or the whole component the rectangle stays the same
Open it in developer tools in your web browser, it looks like your CSS styles have added a fill to the radius curve that has appeared on the wrong side of the curve.
I removed all my classes and it’s still there, although not visible becuase it is the same color as the inactive tabs. Looking in developer options I see: