This is a known issue in V4S Kiosk
Once the Volunteer has Checked Out of a Job or Shift from the Signed up list, please do not close the signed up Volunteers pop up list immediately. Please stay on the screen at least for 15 seconds and then close the pop-up.
This is because if the Volunteer closes the pop up immediately after they Check-out the Volunteer is actually Checked Out of the Job/Shift, but the button takes time to change to show the Check-In button again.
We will fix this issue soon.