I had creatures with exhaust abilities in play, and on each of my opponent's turns I was able to activate them endlessly as long as I had mana to pay for them.

Platform: PC

I assume this ability triggered by Elvish Refueler that basically works like: "on your turn as long as you not activated an exhaust ability exhaust abilities may be activated like if they wasn't activated before", so basically if you haven't activated an exhaust ability on your turn with Elvish Refueler in play, your opponent can activate their exhaust abilities as many times as they want as long as they have mana for it.

This bug needs to be fixed as soon as possible, cause it basically makes Elvish Refueler into a gamebreaking card for any uninformed player as long as game ends up being in uppermentioned circumstances.