> ... but I didn't clear it's status flag, ...
Not sure what you mean.
Unlike TXE and RXNE, the error flag are not cleared automatically by accessing the UART RX/TX register.
> Will it be interrupted all the time?
No. But it will prevent you from receiving any further characters (and interrupts) if set.
Check, handle, and clear the error flags inside the interrupt handler routine. Or the callback, if you work with Cube/HAL.
