I confirmed I removed the yellow film covering the slots for the capacitive paddles.
I find the paddle sometimes become not very responsive. In the beginning, I will be able to send regular dits and dahs. As tise goes on, there will be missing dits and dahs.
I have attached a video.
Also, using my single lever Kent paddle, I sometimes need to tap the dit harder than when the paddle is connected to my FT-450D rig.