I make an event (event A) and pan something to the right.
Then I make a new event (event B) and use event A as a nested event inside.
The pan is not retained, so when A is being played as a nested event through B, there is no panning.
The same thing happens with referenced events.
Are you using any sends or transceiver effects? Both create a copy of the signal as it is at their position in the signal chain, so a send or transceiver effect positioned before the panner will send the non-panned signal.
What channel formats are your tracks inputs and outputs set to? You can check by right-clicking on the input and output meters of each track and seeing which item is checked in the context menu. If any of your track is upmixing or downmixing the signal to a different channel format, that might explain the behavior you’re seeing.
Does your event include any spatializing effects? Under some circumstances, spatializers can redistribute content across a number of channels.