So Mike, I actually got trained to use Audio/Nexia now, but just been to busy with other things to reply to this thread until now. I can upload a snapshot of the Nexia in the system into this post.
Most likely if you scroll that screen up you will find the block of input meters, watch the meters and if you see one of meters show a level spike at the same time you hear the noise then check that connected input source.
If any of those inputs have an open room mic on it you may see two level meter spikes, one from the source it self and the other from the mic picking up the noise. The direct source should be the higher one.
Of course the noise maybe coming from the output of the DSP or even further downstream in that case the input metering would not show it.
For the input meters to be active you need to be in the online live mode.
If the meters are not below the layout block click on the peak meter block.