My partner and I were booked and confirmed in F on LH450 on May 20 , LH changed the departure time and now we can't make the connection coming up from Lisbon.

LH rerouted us via Munich now in Biz and not first. They won't release seats to us as they have no award availabilty, which I think is BS . If they have availability on May 20, they will move us up.

So, my question is, should we roll the dice and continue on with LH hoping to get back into F, or should I have United move us to the UA flight out of FRA/LAX and force open seats for us?

Is there a UA First Class lounge in FRA or is it just a RCC?