I suspect the OSM search function uses Nominatim and if that’s correct then is there a reason Nominatim doesn’t see the relation? Or something I can do to get it to show up?
I suspect that Nominatim simply hadn’t caught up with your edit when you checked. There is a daily maintenance window between 2am and 4am UTC where Nominatim falls behind on updates and your edit fell in the middle of that. If you look at the upper right side of https://nominatim.openstreetmap.org, you’ll find the date, when Nominatim has last consumed data. If it is behind, give it a few hours to catch up.