How it possible that one official authority (UK Foreign Office) knows Hewa Bora is not ICAO compliant (presumably it based on UK CAA opinion?) but other authority (Belgian CAA) allows them to operate passenger scheduled services out of Brussels?
Think of the historic political ties between Belgium and The DRC.
This only started around 1890 but in 1894 the country was renamed the Belgian Congo.
Just another way of keeping the finger in the pie.
Most other countries do the same and ignore criticism from other sources regarding safety lapses, abuses etc.