Grove Voltage Divider measurements are not accurate or stable

I do not have an Arduino to test, although I read the wiki page more along the lines of saying that the software wasn’t necessarily fully supported and test, but I assumed hardware wise there wouldn’t be any reason why the Grove HAT for the Pi would work differently for analog reads than the Arduino. That might be naive though, perhaps you have more insight into what exactly might be different and why that would affect this component?