It’s possible that you see a shift in your dashboard which says ‘you cancelled’ when you didn’t do this yourself. The system will have done this automatically for you. There is a reason why this could have happened:
You’ve applied for multiple jobs that fall within the same timeframe. As you were accepted for one of these shifts, you won’t be able to work the other shifts you applied for. For that reason, the system will automatically cancel the shifts where the time frames overlap.
Or, it is less than 8 hours before the start of the shift and when you applied for the shift, you chose to cancel your application automatically if you're not accepted 8 hours before the shift starts.
Do you still actually want to work a specific shift? Read how to recover your past applications.