Can't Change Relative Date Slicer

Is it a known issue whereby you can't change a relative date slicer back to an ordinary list/slider? The drop down to change slicer type isn't appearing, even when I increase the size of the visual. I have extremely complicated interactions so deleting and re-adding the slicer isn't an option.

The Power BI software is great but there are still a hideous number of basic bugs and missing features