Hey there. Mods can be refunded individually this season rather than always having to reset the whole artifact. Depending on your current mod combination, it may not be possible to refund certain mods. Like if you have a mod purchased in column 2, you are not allowed to have less than 3 in column 1. It will show 'requirement not met' on these column 1 mods. It is a message referring to the refund system and not in any way to do with the mod's function.