I am in the same boat as the OP. I am traveling MUC-CDG-MUC in the next couple days. Called UA and no LH flights are available, even though ANA shows every flight is open for the days I want. I was bumped. Then I remember that I have some USair miles in my account. Called USair and bingo! Flights are available exactly as ANA indicated. That is a solid proof that UA don't have full access to LH flights, either LH blocks them or UA has no money to pay up. Furthermore, the tax and fee for USair's flight is only $51, but UA wants $95 (connection in Zurich)!

There are some low cost carriers that fly MUC-CDG route. OP may want to check them out. I looked into them and they were about $200 RT.