Hello and welcome.
In removing the camera lens, you have also removed the mechanical shutter that closes AFTER the image is captured.
I had a similar effect with a lensless camera mounted on a microscope.
I had to make a tiny shutter using a pager motor and thin metal shim from feeler gauges.
If you have photos of your camera conversion, I would be interested in seeing large images, preferably here otherwise contact me.
David