Hi Joe,
I had the same 5% brake bias on my Clubsport pedals as well. I complained several times and while it took Fanatec 3 months to figure it out, they did send me a new smaller diameter "PU Foam" piece that goes into the brake. I have not noticed the bias again since.

If you want the guy's email at Fanatec who I conversed with send me a private message.

Responded via PM to Wrecking Crew, but I can also post here for everyone to see the info. Ultimately Chunx pointed out to me that adding a bit of deadzone at the beginning of the brake response can help to eliminate the Clubsport brake dragging, without effecting braking response or performance.