Hello and welcome,
Are you able to share the location of the Wayspot in question? We’d be more than happy to look at the S2 cell location to see if it meets inclusion rules. Keep in mind if you are using a 3rd party map to determine S2 cells, these aren’t always accurate.
PoGo uses S2 cells to determine where stops/gyms are in game, and it could be that there are other Wayspots that are already stops/gyms in the area, so this Wayspot could be an unused one, thus becoming a Power Spot.
I myself have nominated and gotten accepted many Wayspots that do not show up in PoGo due to the S2 density rules, but do sometimes show up as Power Spots. Not all unused Wayspots in PoGo do get used as Power Spots though, as many were imported from a 3rd party database.
More info on S2 cells in PoGo can be found here:
https://pokemongohub.net/post/featured/comprehensive-guide-s2-cells-pokemon-go/
More info on Power Spots can be found here: