Image-heavy forms take longer to fully upload - thirty to sixty seconds - depending on variables such as the number of images, device type and connection strength.
App users in the field may lose signal strength while a form is uploading.
The Forms InProgress screen shows the "Pending Upload" to a user during the time it takes for their submitted form to fully upload.
The addition of the Pending Upload status helps ensure end-users allow their forms to upload fully, including any/all images captured in the inspection/incident/meeting form.
If you are having connection issues, please read this article on how to reset your wi-fi connection.