Why is Apple Pay unreliable at Aldi and Podcast app causing freezes on iPhone XR?

At Aldi, when using Apple Pay and Apple Wallet on iPhone, often takes multiple attempts to succeed. Also, on separate occasions, if Podcast app is engaged and I take a photo, with Camera app, the screen freezes, preventing switch from Camera app to any other app, in addition to which Podcast stops playing and disappears from engaged app section, when screen wakes up. iPhone XR, iOS Version 18.4.1, 192 apps and 55.88 GB of 64 GB used.