Query - reading the manual, it says when replacing the cabin filter to "Detach the leaf screen housing container".
Trying to see where that is...............................is that the thing your putting sealant on the top edge of?
I note the bloke in the Youtube Video didn't do this, he just pulled the filter out and up.
There is a screen in the spot that the filter goes. You pull that out, chuck it away and insert the pollen filter. I add some adhesive foam seal along the top and that give the filter a perfect seal. They are never quite the right shape.
This shows, the positive battery terminal, the air intake and the area when the filter fits. If you get some silicone in behind that lip where the plastic housing meets the firewall. A trim tool can pry that out enough to get a silicone nozzle in there without scratching the paint.