When I select an image style of “circle” I seem to get odd effects with the background content colour. Sometime the content background is circular and sometimes square. A solid colour will always show a square background. When I choose some opacity, then I start getting inconsistent results, sometimes a circular background (which is what I expect and want) and sometime a square background and sometimes if flashes between the two, that is starts of square and ends up showing just the circles. And once black ??? Eg.
The top picture is what I want. I often get this happening when I preview “Full Width”, but when I preview in iPad or iPhone, it always shows the solid background.