Hi I am Cheng who is a UChicago student. Recently I am running a 1D nanobeam cavity simulation. However, after I ran it a few times, I found the signal always has some divergences as time evolves. Sometimes it leads to a warning but sometimes it just bumps up a little, but overall either one does not make any physical sense. Could you please help me take a look at it, to see if I made something wrong with the simulation setup? Best Cheng