Hi Bertram,
Sorry to hear it’s taking a while for your bees to take to your Flow Frames. I would not give up just yet 
I had a look from your post last year, and it looked like your hive swarmed soon after you got them into 2 brood boxes. I wouldn’t say this was a failed Flow Frame attempt, the bees didn’t even get a chance to try them last year.
I have not seen any beekeeper in real life or on the forum start with 2 boxes straight away… but maybe it’s done and I missed it. I thought the bees are better off in a small space, as they need to build up their frames, brood, and honey, and then add a second box, whether that’s a second brood box for your climate or a Super for honey storage.
I am not an experienced beekeeper, but if bees are moving honey around, or eating it - then they need to eat it.
If they need more space to put the honey - then they will move to the empty space and start to fill the empty space with honey.
Because you might have a shorter season in Germany, I would definitely recommend painting your Flow Frames with wax. There are some videos in the topic that Dawn posted earlier.
The more wax on them, the less wax the bees need to produce initially, and the more they smell like home 
This picture shows you what they have to do first: 
I understand it’s hard to wait, but I am patiently waiting for my bees to move up as well I moved them last week, so I know they are also getting used to the move, etc, and building up stores.
You are welcome to email customer support @Forum_Support if you would like further assistance, or post some more photos of your hive and Flow Frames on here, and the experienced Flow users will be able to help you.
