I also live in a very rural area.I agree with @Miami Reef, the aeration test results do not make sense to me, particularly one you aerated outside the house.
The most common cause of low pH is elevated indoor CO2 levels. Your test result would indicate that both indoor and outdoor CO2 levels are elevated and they are similar. I’m not sure what to make of that.
Do you live is city or area with a lot of car traffic? I’m grasping for something other than a probe issue.
