A new bug has emerged in Diablo 4 Season 5 where players who had unlocked Tempering Recipes in Season 4 unlocked them immediately in Season 5 – and this will not be hotfixed according to Blizzard.
Some players logging into Season of the Infernal Hordes noticed that something was amiss – the Tempering Manuals they had unlocked in Season 4 were still available, and they could use them immediately.