The render elements update with the global output path, but when I save and reload the 3dsmax file they are wrong. The wrong path and also without a file extension. I then have to delete the render elements, and re-add them. Then they will update with the global path again. But every time I open a 3dsmax file they are set to a wrong folder and do not update with the global path. I know this is a known bg. But does this happen every time I load a 3dsmax file?
Which Max version? I guess this is not related to Corona, but maybe to a certain Max version. Works fine here in 2016 for example.
3dsmax 2018.2
Haven’t used 2018 in production yet. You could try installing PU4 and see if that helps. Who knows, maybe they’ve fixed it.
2018.4 has other problems 
That’s why I am still at 2018.2