Im having issues with the Skeletal storm mage support skills

I thought I have looked everywhere and it's pointing to a bug, or I'm stupid. All the support gems i try to unlock for the skeletal storm mage say this support cannont be socketed into this gem but it clearly can. I have never unlocked the support gem before either.

For example the conductivity support gems isn't available for me to unlock but the ignition support gems is and I can equip that to the storm mage but what's the point... please help!!

Do you have them equipped elsewhere? Do you have the stat requirements met? When you go to engrave a support gem and go to the skele mages are those ones you want to equip listed there ?