@Jarl-Penguin Just uploaded the datapack to the ticket — the potion in question is part of an overwritten version of the vanilla Desert Pyramid archaeology loot table. If you run the command "/loot give [Username] loot minecraft:archaeology/desert_pyramid" several times, you should be able to spawn one.
Still an issue in 1.21.5 — this is incredibly annoying when trying to give players permanent stat boosts via datapack.