Done Witchery Arthana bug or not?

I have problem - when I place arthana on altar is looks like its placed down but when i click empty spot where arthana was it's still there so i have a question:

This is the bug or this how it works - arthana is on altar and its working but u still have one in inventory?

 

It's been a known issue for ages. Fortunately, the arthana is rather pointless if you set things up correctly. I personally build a Witchery 'power' chamber under my altar and can easily max out the Altar Power.

If you need help with your Altar power, my favorite reference is here: Altar (Witchery) - Official Feed The Beast Wiki
Hope it helps