Cannot harvest swap legacy "elemental resistance cannot be penetrated"

Cannot use the harvest bench to swap "Lightning Resistance cannot be Penetrated" mod from Necropolis league, despite the mod being tagged with lightning + resistance, and having another similar-tier modifier (Fire/Cold Resistance cannot be Penetrated).

I'm not sure why this would be expected to work. This mod does not grant Lightning Resistance.

Technically, +X% to maximum Lightning Resistance doesn't grant Lightning Resistance but still can be harvest swapped. The mod does say Lightning Resistance and does have the same tags as the Lightning Resistance mod. I would have expected it to work, even if it doesn't explicitly says +% to Lightning Resistance.