I had similar issue, I bought new rubbers, but ended up not needing them because I found a small piece of rubber in there and cleaned it all up and it was fine after that. I read that you can soak the rubber pieces in mineral oil to bring them back down if their swelled at all.
I know you said you installed new clutch rubber, just offering some info on what helped me so not sure your having having similar issue. I also scoured and clean the surface of the bell where the clutch contacts just for extra measure.(edited)