Thanks Tim,
I tried making sure the div had the right size beforehand by setting a dashed border and it looked like it was more than large enough, but if I set flex on the visualization/visualize in CSS it still only took up the top line as in the previous image.
If I use block display on those elements I can get the visualization to appear, I just lose the responsive design which is ok for now. For some reason my timerange of 90 days is not displaying properly so I will need to investigate that next.
With block:
