As mentioned by @RAc there are many posts here in the forum regarding interrupt priorities especially related to wide spread Cortex-M MCUs.
Search for configMAX_SYSCALL_INTERRUPT_PRIORITY and/or configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY.
However, did you already read the FreeRTOS docs (in case you’re using a Cortex-M MCU as I suppose) RTOS for ARM Cortex-M ?
IMO this post Understanding priority levels of ISR and FreeRTOS APIs - #16 by aggarg contains a good and easy to understand explanation. There are more…
BTW: You should always include the MCU or the processor core and the FreeRTOS version you are using when asking for help.