Sapphire S_ZBlur and S_ZDefocus in Resolve

Hi there.

I am testing out the depth blur nodes in the Fusion section of Resolve and found this strange issue.
The blur node (both ZBlur and ZDefocus) seems to mess up the alpha channel of the objects that are in focus. It is targetting the edges specifically.

For the depth map I use an unfiltered image (with aliased edges):

Are there any best practices to avoid this type of alpha fringing?

Thank you for your help.