Hi @husman, I think it might be related to this.
You can find more details in the linked post, but in short, some neurons had age bonus while dissolving, caused by a bug introduced a while ago, and the change to correct it (remove age bonus for dissolving neurons) took effect on May 27, which made affected neurons to have correct (but lower than before) voting power for proposals created after that. Typically proposals settle 4 days after their creation, so the timeline seems to fit.
Since you mentioned that you have another neuron, perhaps you can check the daily reward / voting power for both, and see if those 2 neurons are rewarded at the same rate, which can hopefully convince you that it’s not that the neuron 11616933042373356616 is getting lower rewards, but it got (incorrect) higher rewards for a period of time.
Hope this helps!