Nano Optics - Single dipole near infinite interface

I am trying to reproduce far field radiation patterns for single emitters close to an infinite dielectric interface. Namely, I place an emitter in air, in the vicinity of a glass substrate (10[nm] above). The dipole moment is oriented toward the interface.

I expect a far field angular pattern similar to the one attached (expected_behavior.jpg where they put the dipole in water instead of air). Instead I get something like the other picture (dipole_near_interface.png).

Light should be directed along the critical angle (in Air/Glass case -> 41 degrees). Instead of that, I find an extremum at around 50 degrees.

I define the dipole as a point dipole. I have PML, but I guess that have two different materials touching could be a problem here. Therefore i want to know if I am indeed limited to finite systems, or if I can model a dipole with two infinite materials .

Thanks for reading,
Jean-Christophe

ps : Model made with C.4.3