Bonded Doublet Lenses do not trace correctly

[NathanKOMet]

I tested making this achromatic doublet lens .
When there is a slight spacing (1μm works) between the two elements I roughly get the focal length that is expected, but when they're in contact the focal length is wildly different. Is this expected behaviour?
If there's any further info I can give let me know. I'm on v1.3.7 of the workbench and Freecad 1.1.1

[chbergmann]

This is another case where the algorithm that detects if a ray is inside or outside a lens fails like this issue
There is no solution for this yet. You can try to move the two lens parts to two different lens objects.