I tried to create a new Preset following the online tutorials. My preset shows up on the top Preset selection at the top scrollbar, I can select it there, but not in the dropdown selection which doesn't change. Result I can't change to my new Preset 9. The only thing I didn't do was create a thumbnail.
Ah ha - sorted! Click on the new Preset, in my case 9 and then select 'Custom' in the dropdown. I thought the new preset would show up as a title - doh.