4*Medusa cannot gain AP when enemy tile matched

In a very long time, a have not use Medusa . Recently, I try to use Medusa to counter Polaris, as per the suggestions in the forum. 

But no matter friendly or enemy match to enemy tile, no gain in AP by Medusa. While matching of friendly tile do giving a brust of health. 

And, when I play Medusa against enemies other than Polaris/Kitty/Bill, it is the same (no gain in AP).

So, I quite sure that it is a bug. Please review, thanks.

 (using Android)