MCP73833 power path problem
You had used a P-channel Mosfet IRLML2244, so due to resistor R30 the gate pin of MOSFET is pulled down to the ground with 10k resistance as shown with a red circle. So the P channel MOSFET will be turned on and a small amount of current will flow from battery positive terminal to gate of MOSFET as shown with a blue line. so you are able to measure voltage on that line.