just an observation, I was looking to book DUB-FRA-BLR in Business using LM on LH for march/april - 3 seats.
there was no availability for any of my dates.
LH had companion sale going on for the last few weeks. it got over last night.
today i checked on LM for my dates, ola now the seats are available.
its just my guess that LH may have blocked or not released business class seats for partner airline awards during their sale.