As Prism is an online system, it allows you to access it anywhere at anytime. However it also means it is sometimes at the mercy of the network online or via your mobile.
For the most part, networks are fine and result in 99% uptime, however wifi can in particularly be patchy, particularly in rural areas.
You may on occasion witness a blank drop down, server error notification or slowness to load, which is a sign that there is a network issue.
For these issues you can refresh the page, click out and back in to try and rectify the situation. Alternatively, you can wait for a stronger network connection, move to a different location or as a final resort, close/restart the app, browser or phone.