You may lift a little like few degrees then pull parallel when removing.
I don’t know why, but I could pull the connector out & in without flipping up the flap. And fans are working flawlessly.
This tip worked for me.
Use leverage with tip of a spudger, it’s not that difficult to pry the cables.
When you reassemble, use a tweezers to put the connector on the right position and push it down with a finger on the other hand.
Grab the neck of the cable when using a tweezers.