Thanks, it looks like you do intend 0 to be interpreted as nodata, as there are many pixels with value 0 filling in the edges.
In QGIS if I Layer > Save as there is a panel at the bottom to define the nodata value. “From” is the value you want to be treated as nodata (i.e. 0) and “To” is a value to use to represent nodata (it could also be 0 in this case).
Presumably ArcGIS has a similar functionality if you’re using that.