That is normal. Follow the steps in the manual to cycle shells without firing (you probably are missing the step of pushing the carrier lock button).
Keep the muzzle of the shotgun pointed in a safe direction, and keep your fingers out of the trigger guard
and away from the trigger at all times.
1. Move the manual safety button to the "SAFE" position (refer to Manual Safety Operation, page 6).
2. To unload a shell from the chamber, pull the operating handle rearward to extract the shell.
3. To unload the magazine, lock the carrier by pressing the carrier lock button (located on the left side
next to the trigger guard).
4. Cycle the bolt to feed the next shell into the chamber.
5. Press the carrier lock button again. Cycle the bolt to extract the shell from the chamber and feed
the next shell into the chamber.
6. Repeat step 5 until the magazine is empty and the bolt locks open.
7. Visually confirm that there are no shot shells remaining in the magazine or chamber