It seems that in my last update to get everything up to API 29, it caused an issue with the Australian Daily Prayer app. It turns out that from Android 9, by default http calls are blocked to encourage everyone to switch to https.
Now, after I released the previous update my Pixel 2 stopped working so while I am waiting for that to be fixed I am on my old Nexus 5, this is on Android 8. Still, today I tweaked the app, (assuming this was the issue), to make https calls to my dailyprayer website. Turns out I already had an SSL, so I didn’t have to tweak anything on the server, just the app.
I have already emailed all those who asked about the issue, and one person has gotten back to me saying it is now working on Android 9 from the Play Store. Hopefully, that is the new norm. APK on this site is also updated.