This is a bit of a long shot, but could you try this edit and see if it helps?

Look in C:\ProgramData\MatrixTSL\FlowcodeV10\FCD\ARM
and edit 32F401RC.fcdx
At line 537 change the '1' to '2'
enable='HAL_NVIC_SetPriority(USART2_IRQn, 0, 2);

Re-load the project (or restart Flowcode)

Uart_1 is receiving data every 500ms on a baud rate of 1200 That should leave plenty of processing time to do other tasks. As long as the interrupt code is just reading the UART char and storing in a buffer, then immediately returning from the interrupt routine. The buffer/array can be as big as yo...

Hi, What you are requesting there is the equivalent of using the Flowcode circular buffer component, which is the best way of handling UART reception. Interrupt handlers always need to be as short as possible, therefore best to save the received character into a buffer and then process later in the ...

What is your target device?

Just to add to Steve's comment, there is some C code in this post, I've not tested it though,
https://community.st.com/t5/stm32-mcus- ... d-p/188501

Followed the instructions given but this failed during install, attempting to fetch components. This appears to be attributed to timeouts when trying to fetch components, possibly the latency associated with cellular networks is contriibuting as the Evil Lab only has cellular connectivity. That's a...

I agree with kersing, according to the log, the space in the username does seem to be causing problems

Yes, it should.
And to change the baud rate add this before HAL_UART_Init()

The problem here is clocks again
To get a baud rate that low you will need to lower the APB2 clock.
Try changing the APB2 prescaler to /4