I have a custom STM32F103C8T6 board. Long story short, the MCU works fine, I can connect to it, program it, read sensors, toggle GPIO etc. The problem is that, one of the crucial pins seems to be shorted to VDD. The pin is PA9, which I wanted use for USART_TX1. I have no control over this pin. I can not digitally toggle it, can not use uart, nothing. I checked the pin via a multimeter ,with the board powered on and off, and both times I noticed a short between VDD and the pin. The length of the track out of this pin is about 7 inches. I visually inspected the route to see if short was on the board but I didn't notice anything, route is neat and isolated. Thus, I believe the pin is internally tied to VDD somehow?
I also performed a full chip erase, still tied to VDD. I also think it is worth noting that sometimes there exists an amount of resistance that the multimeter measures when checking for shorts. I read values ranging from 2 to 190 ohms.
What is going on here?
Edit: schematic and layout of the relevant parts. Top layer being ground, and the bottom being VDD. Let me know if more info is needed.