Shutter release cable with d3200 = Only 100 Images?

I'm shooting star trails with my d3200. I am using a wired Shutter Release Cable.

My star trails shoot just fine, but only up to 100 images. The memory card is not full, but the camera just starts ignoring the shutter release cable until I unlock it and re-lock it. Anyone else have this problem?

I'm in manual focus, manual mode (30 second exposure), shooting raw on a class 10 32GB sd card. I noticed noise reduction causes gaps in the trails so I have that turned off.

Any suggestions?

Try turning it to bulb. I set the trigger and let it stay open for 15 minutes or more. Iso 200/f10 0r more. I will have to try it again with the settings. I haven't done it in a while.