I adapted the memory reading to sample D55E6B278DF275851A879E18AC6D96EC04698E31.
You can find the change at:
https://github.com/Arcitectus/Sanderling/pull/52
After this change, I did not notice any discrepancy between the screenshot and the memory measurement.
Let me know in case you see a reason to not merge this into the main branch.