Missing Positron Annihilation Peak in Na-22 Decay

I am building a simulation (Geant4 v11.1.0) based off of the rdecay01 example, where I am calibrating a Germanium detector. When I use Sodium-22 as the particle source, I expect to get a large peak at 511 keV, corresponding to the Electron-Positron Annihilation from the Positron produced from the beta decay. Instead, I get a dip at that location, seen here at the first black dashed line:

I have tried changing physics lists and returning to older versions of Geant4, and I either get the same result or no data whatsoever. I have also tried switching the material from Ge to NaI, but that still gives me a similar result.

Would someone be willing to take a look at my simulation? I currently have no idea where to approach this problem from here.

Here is the simulation file: TestCAL_8-1-23.tar.gz is available for download
Sorry if it is too large (~2GB), there are a lot of .root files in there.

Thank you!