Hi. When I was playing ranger veteran today on War Camp Legendary (private solo game), I used career skill and then drank a concentration potion (with decanter) (or maybe I drank before I ulted, but either way, the initial ult was already ready for use).
When the bar filled again, I used career skill again. This was before the first one ran out. It created a new ring and smoke and played the sound, and removed my first ult as well, but it had literally no effect. Did not make me invisible, did not grey my screen, and did not proc exhilarating vapours.
Is this a bug or a design choice?