Try filling the bowl with AVB and run a burnoff at about 435F(cannabis combusts at 451F) and blow through the air inlet at the bottom. This worked for the terrible taste of a new Boundless Tera stock mouthpiece and the Starry as well. As long as you don't have a counterfeit Ace made with improper silicone the silicone is usually food grade high temp silicone and safe as well as inert from heat.
Hey thanks for the recommendation and the info about silicon!
I did the burn-offs around that temperature (220-230 Celsius), around five of them outside when it was storming (without the mouthpiece so that the wind could blow through the oven). I also have blown through the air inlet.
All my vaporizers didn't emit a smell like that, except for a Flowermate V05. The seller said that something was wrong with it and replaced the unit.
I'll try to put some herb in it to see if that helps.