Legend: 
Time axis is date:
Please help - I googled “[R]” but can only find things about plotly R.
Hey @teddy_c weclome to the forums.
Could you add code + data so we might take a look at this? It will be pretty hard to help you without knowing more. I general plotly uses the information found in your data to create axis titles and legend entries.
This looks like you are using the package Plotly-Resampler but I cannot be sure without the code. If you are, the [R] tag is a resample of your data. I would check if your figure is wrapped in the FigureResampler or FigureWidgetResampler to disable it. See https://github.com/predict-idlab/plotly-resampler and https://predict-idlab.github.io/plotly-resampler/v0.10.0/ for further information.