Anyone have an idea why this has started to happen?
Below are three screenshots. The two with black lines are SU and LO. All normal. The third is once exported to PDF. Suddenly all lines are pale grey. There are no Tags apart from Untagged and I am using my normal style which only uses monochrome.
I have a workaround. If I print to PDF, it looks normal. I used to only do that until I found that exporting resulted in smaller file sizes, so I am reluctant to go back to printing.