INA219 Voltage measurements meaning
According to the &quot;instructions&quot; for your break-out board, one should:

Power the sensor itself with 3 to 5VDC
connect the two I2C pins up to your microcontroller.
connect your target power supply to VIN+
and the load to ground to VIN-

There are similar instructions here

Connect V+ to the positive terminal of the power supply for the circuit under test.
Connect V- to the positive terminal or lead of the load.  This puts the sense resistor in-line with the circuit.
Finally, connect a wire from the negative terminal of the power supply to GND.  This allows the sensor to measure the load voltage as well as the load current.

If your schematic is correct, you do not appear to have done this.

VIN+ is NOT connected to the target power supply in your schematic
the load is NOT connected to VIN- and ground.

If I understand correctly, your circuit should look something like this:



simulate this circuit &ndash; Schematic created using CircuitLab