vTaksDelay stops scheduler without resuming it after a few calls

I have implemented the vApplicationMallocFailedHook() as well as the vApplicationStackOverflowHook() and these do not get triggered.

There is only one interrupt in my own code that can occur during this, which is when the cellular modem sends a command. My code needs a UART receive-idle interrupt for this, which fires after a serial command line has been received from the modem.

Could this interrupt be messing with vTaskDelay(); ?

I’m very new to FreeRTOS so I’m probably overlooking some beginners mistake.

I’m running FreeRTOS 10.3.1, generated by STM32 CubeMX