Average inventory units stored not showing on revenue calculator

I'm hoping someone can help as I've tried contacting seller support about this issue and getting vague responses. I've noticed my revenue calculator is not showing any numbers on the 'Average inventory units stored' section for any of my ASINs.Every time I load it up it shows as blank not even a '0'. Dose anyone know how to fix this as I'm getting the wrong information about my profits due to these numbers not showing. Thank you