Cloak of Tawm'r Isley + Dark Pact not working

Cloak of Tawm'r Isley has "Socketed Minion Gems are Supported by Level 16 Life Leech"

Dark Pact is a Minion gem, yet it's not getting the leech support :(

Bump with a bit more info:

Dark Pact CAN be linked with life leech, but won't get it from the robe.
Dark Pact DOES work with +2 minion gem prefixes.
Dark Pact IS obtainable through The Summoner divination cards.
The robe WILL apply life leech to Convocation and the Offering skills, despite not creating minions.

Adding info to show that +1 Minion Gems does apply to Dark Pact.