I’m also finding that not 1 bait station or trap is shown in the screen until they’ve all synced. And the syncing just goes on and on. So I click the button and choose ‘Sync Now’ which does work after a short time.
Your phone shows H+ at the top which means it is operating on 3G rather than 4G.
3G is being phased out later this year I believe, best to check with your provider, but getting a reliable connection on 3G might be challenging as it goes through the phase.