Adding data columns for multiple variable time series plot

Hello, I’ve started working with plot.ly to make multiple variable time-series with remotely sensed data. I discovered that when I added data columns to the right of the first column of numeric data (the first two columns are the time column and the first column of numeric data), the new plot would not show the new data trace. However, when I created a column to the left of the time column, and put a new column of numeric data there, it worked fine.

It would seem logical to add data columns to the right of the first two columns, as those columns already exist! Is there something I’m missing that would make this work that way?