yes.. they are very strict regarding about business visa.. I have a friend with the same type of visa (business visa) around 4 times he is offload from his flight. the corrupt immigration was questioning him some stupid questions like "what is your business here in Philippines & why your going to qatar and blah2x.. he ended up paying 30,000Php for an escort... those corrupt Philippine immigration should be stop... TIPS: dress up professional way and answer them directly without any doubt and fear. Dont bring big luggage.

good luck!