Can erase segment but not draw

Slicer 4.11.0
Windows 10 Pro

Hello, hopefully this question has not been answered before. If so, please point me in the right direction.
I have a patient I am trying to create segmentation for, in order to 3d print the results. I am working off two different MRI scans of the patient, one of these volumes is Axial, one coronal. I created the segmentation off of the Coronal scan, like so:

But sometimes I’ll jump over to the axial view (by loading that volume) to cross reference what I’m doing. When I’ve loaded that axial volume I have two questions:
1- It seems to get all blocky (like the below picture), anything I can do to fix that?
2- I can use the “erase” segment editor tool to erase things that are clearly in the wrong spot, but if I try to “paint” a segment, it seems to only work if my paint diameter is 3% or over, if its 2% or smaller I’ll paint and nothing shows up. When I do get something to show up using the right diameter brush it seems off center of where I painted. Any ideas?

Have you tried draw a circle and then right-click mouse to accept it.


Or try to update the slicer to see how it goes.

That helps workaround the “not working” problem, but it still comes out blocky, see below:
image image

could you check the two scans volume-info firstly to see if they are matched? When you do cross-reference, is there any resampling ?

You selected the DWI volume as master but you’re segmenting the anatomical MRI.

Either create a new segment and choose the proper master, or change the geometry of the existing one (click the box icon next to the master selector and choose the MRI as reference - you can make it isotropic etc too there).