Or move the WP, as was brought up in this thread. I’ll go out on a limb and say there isnt a WvW player who hasnt gone to repair in SM and run into this same thing.
The repair NPC either needs to come down to the WP floor, or the WP needs to go up to the repair NPC (another design issue, unrelated but similar).
https://forum-en.gw2archive.eu/forum/pvp/wuvwuv/Location-of-repair-dude-in-SM