Cast on freeze bugs out freezing mark

Strangely, putting freezing mark in cast on freeze makes the gem unusable after that.

Subsequently trying to equip the freezing mark gem as a stand alone also can't be done. When clicking on the details arrow, it actually shows the skill below that instead (mana remnant in my case). And it is unselectable as a skill in the hotkey bar.

To test, I made a new freezing mark. Worked fine as a stand along skill. Put it into cast on freeze, same problem happened. Put the new gem as a standalone spell, again unusable. Doesn't seem to have any issues with other gems. Don't recall having this problem in season 1 either.