What probably happens is that the event (signals) that take care of the visual update of the progress bar are lower in priority, so although they are sent, the progress bar visual display does not get updated but only at the end of the critical section in the code.
What probably happens is that the event (signals) that take care of the visual update of the progress bar are lower in priority, so although they are sent, the progress bar visual display does not get updated but only at the end of the critical section in the code.