Chances are your trans is OK. Porsche tends to build other things in the system to be weaker and they break first. YMMV.
If it was me, I'd replace both arms, as they twist easily and see if that solves your problems. Had on 09 Box S a cpl yrs ago that had a broken plastic end on the pass side (and a bent arm). Replaced that arm but the clamshell wouldn't close flush. Turns out the driver's side arm was bent but not enough to crack the plastic end off.
Here's the driver's side next to the replacement pass side.
