One Module Reading Higher Voltage

I've been reading these forums for some time now, but I've run into a problem that I haven't seen anyone else mention.

So, I got the christmas tree dashboard on a 2005 Gen 2 Prius with ~160K on it some time ago, indicating a problem with the traction battery, which the mechanic confirms. Having already read up on repairing/reconditioning the battery pack, I decide to simply replace the one bad module with a new one at a similar voltage to the rest of the good ones (7.5V) without charge/discharge cycles or anything as a short term fix while I save up for a new or professionally reconditioned battery pack.

I did it. It worked! For about 30 miles, and then the same lights and warnings came up, so I tore down the battery again and tested each module. They're all fine, reading between 7.48V and 7.52V except for the one I replaced, which is reading 7.62V. I have been unable to find other reference to anyone having had the problem of one module reading significantly higher.

Can I just discharge this one with a light bulb back to 7.5V even though it started off in line with the rest? Does this indicate the module I got was bad? Is the higher voltage a red herring?