Yes, I was referring to them but the same risks apply to them (as with any OTA).

On ITA Matrix, you can find the flights as LH flights / LH codeshare flights so you should be able to get these flights by calling Lufthansa (if you mention that it's not bookable on their website, then they might waive any specific booking fees; I'm not sure on LH's policy on this but BA waives the fee for stuff that can't be booked online with them. I'd therefore ask. Worst case scenario is that they tell you no)