Sorry, I am not an expert, but I understand the need for trickle vents,
but
are you saying that it is normal to have OTHER gaps in the roof to allow
air
out and insects out?

I can't comment on your individual case. Perhaps they forgot to put some
seals in. Obviously, the amount of ventilation should be limited.

The conservatory I built recently had a double glazed roof, with rubber
seals entirely sealing the window units to the frame. No specific
ventilation was provided.

Christian.