A Z-Wave "Repair" isn't going to fix a node that isn't really on your network or never fully included. In general, this operation is rarely necessary on Z-Wave networks with Z-Wave Plus and newer devices and will fix (or expedeite fixing) specific problems that mostly related to routing.
You're going to need a "Remove," which may appear on its own eventually, or trying a "Refresh" may make it appear sooner. Basically the steps I recently outlined for someone else in this topic:
As for whether it will cause problems: it's good to avoid this if you can and not a guarantee of problems if you can't. So you won't know until if or when you have problems, but if they relate to Z-Wave specifically, this would be a good thing to look at then if you can't before. Patience is key, however, as it may look different in a day or two than it does now.
