Chimney ventilation questions

Im not sure if I am posting it correctly as it is my first time using this forum and I am a concerned tenant who needs advice from those who will have more understanding about building than me.

i rent a flat that used to have a chimney which has been covered up in concrete (probably a long time ago) and i started noticing recently that my son would cough when in close proximity to the vent and i thought maybe it was clogged with dust.. so i decided to open it with the intention of cleaning it. And upon opening i found a very rough hole and a layer of grey fibrous material. I am terrified this could be asbestos as we would have all been exposed to it. I took a sample and sent it for asbestos testing independently and I am awaiting results. I also contacted the landlord and surveyor who have said that the ventilation has been installed properly.. but that If i am concerned they can test the material to see if it is asbestos.
Now my question is:
- from the photo of the hole, is this the way the ventilation its meant to look? Or is this a poorly done job?
- if it contained asbestos or any other hazardous insulating material, wouldnt it be required to block that to ensure that it doesnt end up entering the flat through the vent openings?
Thank you for any help from a very anxious mum