This is not fixable unless you use a different node structure.
I can’t find @jkutilek’s explanation anymore, he linked a very good resource a few months ago explaining the mathematics behind this. (Sorry for tagging you if it wasn’t you, Jens!)
Otherwise: https://twitter.com/RafalBuchner/status/965232476259004417
TLDR you’ll have to place the nodes from your first screenshot so that the angle of the handles stays the same.