Opening segmentation without mastervolume

Operating system: Windows 10
Slicer version: 4.11.20210226

Hello, I am new to slicer and have a problem with opening my finished segmentation without a mastervolume.

I use a dummyFile (.nhdr), generated with my original binary data (CT), as the mastervolume for the segmentation.
When I open the finished segmenation and the dummyFile, I am able to view all slices.

But when I try to open the finished segmentation (.seg.nrrd) without the mastervolume, only three of the 512 slices (that I can usually choose with the scroll bar) are shown. The scrollbar directly jumps from one end to the middle to the other end.

Is there a specific way to save/export the segmentation (should still be .seg.nrrd or .nrrd), so that I can open it without the mastervolume and still be able to view all slices?

Thank you in advance!
Laura

Additional video:

First you can see the segmentation with the master volume (dummyFile) and then without the mastervolume.

Without the mastervolume the red scrollbar jumps from -1.0000 to 0.0000 to 1.0000, whereas with the mastervolume it ranges from 0.0000 to 255.0000.