Issue with segmentation on non-axial volume

I have been trying to segment a series of MRI scans however when I use the paint tool to highlight a section on a single slice it seems to get split over neighbouring slices.
I have attached a screenshot to help explain.

Would anyone please be able to help me figure out what is going on?

Segmentation issue (1)

You have a non-axis-aligned volume. For slice-by-slice segmentation it may be easier to align slice views with the image plane as described in this topic:

Hi, thank you so much for this!! It seems to have solved our problem, I never realised that button was there to align the scans.

Thanks again, your help is greatly appreciated!