I am using version 9.01 although the previous one (9.00) has been also affected.
I prefer to have darker background so I have used a theme downloaded from this forum called MinimalZen.
With versions 8.x it has worked like a charm but now the dark background ends with the last line of text and then is the white background.
Checked another theme downloaded from this forum (Dark) works in the same way.

Also I have noticed the switching themes (and before choosing "Properties for all configurations") takes a long time (maybe 30 seconds).
I have upgraded to the newest version from version 8 without uninstallation older version. Maybe here is a problem? I don't want to loose my settings so do it in this way.