Sounds exactly like my clear first run Russian CFR C-Line FD. I saw a production stamp C-FD at disc golf center recently that was also heavy and clear, very domey. You're probably right, leftovers from the first run. I've been hoarding spare flat ones just in case. If a new run ever comes out domey or flippy, I'll be prepared.
Have you thrown in yet? The domey ones aren't terrible, but they feel slower and flew more turn-then-fade for me.