Solved
USART configuration problem
Version: 1.14.1
MCU package: STM32CubeF1 Firmware Package V1.8.0 / 26-June-2019
The GPIO Settings of the USART auto configuration are incorrect.
The decades-old STM32F1 series handles pin functions differently than other series. Since USART_RX is an input to the microcontroller, input mode is correct and appropriate here.
AF is used for outputs and bidirectional pins.
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