Concentrated Effect lvl 21 not working with Flame Surge

Hello! I just got a lvl 21 Concentrated Effect, which is nice, except that it did not make any difference at all in the dps of my Flame Surge (with Spell Totem).



As you can see, the damage is very much the same with both a lvl 20 and a lvl 21 Concentrated Effect.

And the problem only happens with this set up of Flame Surge, I tested with my Fire Trap and it increases the damage just like it supposed to do.

Is this a bug or am I missing something here?

uppp