Aahh, okay I get it 100% now. Both chip are present on the board.
Top layout
The STM32F103CBT6 on the bottom of the board is the ST-Link flasher. Yes, the ST-Link is just that chip with a special firmware, that’s all it is (docs)
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The actual target microcontroller on the board is the STM32L432KC, residing on the top side of the board.
So you’re not wrong to read the chip number STM32F103CBT6 on the board, but it’s not the right chip 
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Great that everything’s resolved now.