Is there a problem with the HV Battery? Gen 2 Prius hesitates.
The graph presented in the image appears somewhat disconcerting, but when one considers the scale of the Y axis, it's not too bad. The text references a voltage difference of 0.07, seven one-hundredths of a volt across the entire pack. The internal resistance difference is also only one milli-ohm across the pack.
At a state of charge of slightly less than fifty percent, the indication is that the pack is getting very slightly out-of-balance as it discharges. Unless you are experiencing difficulties, or have specific reference material suggesting a problem, you appear to have none.
Consider to examine your pack in the same manner after a charge and also after a drive of a few miles, which will be more illuminating.