A battery that load tests as bad can be charged a dozen times and still not perform (and it can certainly show good voltage in a STATIC test). Load testing is important vs charging and ONLY measuring the volts.. After that, the bottom line to starting is the cranking rpms that you need. You need 150 minimum. You were not showing that you were getting that before. You STILL may not be getting that, but the data needs to be posted. IF the batteries are good (which IMO is STILL an unknown without a load test), then maybe an accessory is dragging, who knows. Troubleshooting is a step-wise process.
You certainly may have checked the batteries out thoroughly, but your post does not reflect that.
EDIT - Something seems top be seriously wrong with your cranking and you need to methodically rule out the possible issues by proper testing. If you are insisting the batteries are good, then do whatever you know to do to rule out a starter issue. Personally I watch the rpm signal when cranking, but you have yet to even respond on that.