That's the problem. Somehow the brown transactions with a feerate of ~600 Sats/vb were taken out in favor of the 23-300 Sats/vb transactions in blue. Obviously they payed ViaBTC some extra Sats internally, but still.. Not quite healthy! Or am I missing something here?

https://mempool.space/de/block/00000000000000000001f88790f3cfdabdca999f64c21b3a4dfe06275f3e91aa