It appears that when both freezing / sorting are enabled, freezing loses its desired functionality. That is, it starts to freeze the left-most unfrozen column instead of the one you clicked on. Here is a fiddle:
Thank you for sharing. I have replicated the issue using latest version as well (7.0.3).
This issue should get solve after we add the global index mapper https://github.com/handsontable/handsontable/issues/5112
I will update you as soon as we get this done and we'll check if it solves the freezing issue.