Sustain pedal works fine here too with every softsynth i have except... wurly v
My answer was about the Wurlitzer V. My Sustain pedal works with the Wurly V in Studio One as described.
Can't tell whats the matter with yours then. But perhaps a reinstall of Wurly V would help. Don't know.
EDIT: I can add the pedal works with Wurlitzer V in both Studio One 2 and Studio One 3. Just tried in Studio One 2 also.
I use a Novation SLMK 2 controller.
I also use the latest update of Wurlitzer. If you don't have the latest update, that might be a coarse. If so then try to update your Wurly.