If you're struggling with problems connecting or starting a payment process with a SumUp terminal, we have a tip for you. This can help you especially if you briefly see a SumUp screen when connecting or using the SumUp terminal, and then the POS app restarts.
Then swipe down from the top of the tablet to open the status bar. And press once on the «Auto Rotate» icon to turn off the automatic rotation of the screen.
Now try again to start the connection or the sale with the terminal. You should be able at this time to work without further faileures.