Why does my iPhone keep timing out when I'm listening to radio 4 extra?

[Chorltonswheelies422]

When I'm listening, it keeps timing out and I have to keep swiping - but I don't have to enter my password. Driving me crazy because it does it every 8-10 mins.

I've gone to settings and changed the time on passcode to maximum but hasn't made any difference.

Can anyone help me please?