Hi Elixira
You didn't say what tank you are using so I have to assume you've got the Baby Beast with that AL85. The problem seems strange in that there is no good reason your airflow would change. Even dropping it shouldn't impact the airflow unless there was noticeable damage and misalignment of the parts which you say there isn't. You say you have cleaned it twice so there should be nothing like say pocket lint that somehow found its way inside and is blocking the airflow.
You can try and diagnose the problem by following the air's path. You say the vents are wide open which is easily seen. the air then travels through the base into the coil, through the coil and up the chimney to the drip tip then through to your mouth. By taking the tank apart you can see through each of these to see if there is a blockage and you can test draw air through them separately to further determine if there is a culprit there. The latter will also tell you which part is being the most restrictive to air flow.
At this stage, and assuming you've not been able to find a good physical reason for the change, all I can do is hazard some guesses.
Guess #1 - Is it possible that you changed the coil to a different type. Though I haven't noticed any difference in mine from one coil to the next, say from the T8 to the T4, but maybe you noticed a difference.
Guess #2 - Are you perhaps letting a finger sit in front of a air slot when vaping, I do that sometimes without being aware of it.
Guess #3 - It is all in your mind, nothing really has changed with the airflow. I don't mean to belittle your impression that the air flow was reduced but sometimes impressions can be wrong.
Good luck with it.