Cast on critical/temporal rift bug

Cast on critical quality for 10% increased reservation efficiency does not work properly with temporal rift. I have 100 base spirit plus 15 on my amulet so 115 spirit. After activating cast on critical with the increase to quality on cast on critical I have 24 extra spirit. While using the clarity II support gem that costs 20 spirit on temporal rift I cannot use temporal rift even though I show to still have 4 extra spirit. I CAN put clarity II on another skill and it functions properly but it will not work with temporal rift.