Gaussian .fchk file orbital rendering

I am currently working on a copper open-shell complex with Gaussian 16 and try to visualise the orbitals with Avogadro by loading the .fchk-file. Whereas it works fine with benzene for instance, Avogadro seems to struggle with rendering and displaying the orbitals of my complex. Even though it seems to finish rendering the first orbital, it does not display it and neither continues with rendering other orbitals. A change of display quality does not make a difference.

Is anyone facing the same problem? Is this due to the open-shell system? Is there a fix for it?
I am working on a Mac with Avogadro 1.2.0 (Open Babel 2.3.90).
Would greatly appreciate any help!