Charlga Bug or by design?

I've reproduced an observation now a few times in pvp where if at the start of a match you wait until you have 9 or 10 gold, then play a mini, all your gold goes to 0, regardless of the mini you play. Like you play one cycle mini and your gold goes from 10 to 0. I think you may have to have Charlga showing in the deck for it to happen. I dont play Charlga much... so please let me know if this is some weird way his "spirit tangle" works, or if its a bug.