Looking into bugs in some algos I'm running and one of the common issues I'm seeing is that the volume data QC shows when I print from research, or here 

is very different from the data from finviz, yahoo, or other sources (all of which are congruent to each other). Anyone have any ideas why there is inconsistency in the volume data? 

Here's an example. First column is QC data right is from Yahoo as an example.