the preset list is rather long. So the top-most presets cannot show the preview fully, for the previews will be shown centered around the menu entry.
As a workaround you could create your own preset group and add the topmost presets to this group. This way you will be able to access them from a shorter menu, and you should be able to see the preview from this group.
To add an own preset group select the "Effects" drop down menu and go to "Edit"
In the "Edit" panel select your " Seim Effects series group" and select "Duplicate Preset" from below the cogwheel in the lower left corner. Rename the copy. Now shorten this copied list by deleting effects, until only the list is short enough to let you preview the topmost effects.