Diagnosing 07 Camry Hybrid problem

I know this is Gen II forum but the same principles should apply to this situation. This is a 2007 Camry Hybrid with 135k. Initially we had code P3022, cell block 12 becomes weak. Found one module in cell block 12 that was over 1 volt different than the rest and swapped it out with a good one. The car ran fine for one day or about 30 miles. The next day I made it about 5 miles and it threw another code, this time P3025 (cell block 15 becomes weak). When I hooked it up to Toyota Techstream it showed cell block 15 reading 16.56 volts. The other cell blocks read between 16.29 and 16.49. A little odd that it was reading higher.

So today we took it apart and tested voltage of each module. They are all 7.86 or 7.87, including the two modules in cell block 15. The buss bars have corrosion on both sides but probably no more than a typical 07 with 135k miles.

Now that all wiring/buss bars are removed I will let it rest overnight to see if there is any degradation of voltage in any modules. If not then I'm thinking my next move on this is to replace the buss bar on both sides and both modules from cell block 15 and see what happens but I wanted to get some input and see if there is something else I should be looking for.

Thanks