Hey endet,
Apologies for the late reply. Unfortunately I did not book the flights yet because I was waiting for some confirmation from my work.
I have seen that the flights are not at the price and the availability they used to nor on Flight Network/BudgetAir/Vayama/etc. I have found that Xiamen is still pricing the flights at the correct price but still in Y for the intra-European legs. My bet is to wait a few days to see if the price reverts to the usual ones, otherwise I do think it is not worth it.
By the way, I have found on BudgetAir a 5 hour layover instead of your 20. I guess it is slowly reverting to what we have seen before
