Upload & Sell: Off
...when I went into the mode with the highlighted "T" (shutter priority) it gave me a F/S next to the number...
Well, you've now discovered Sekonic's hidden bonus feature: the standard 558 and 758 have a subset of the Cine models' "Frames per Second" metering for shooting motion pictures. As you found, you just keep scrolling to get back to still-camera numbers.
Glad everything worked out.