I thought I must have accidentally opened the diary event and somehow fumble-changed it so it no longer had a notification attached the first time it happened, but then it worked fine the next day. It didn't work yesterday and I looked at the event and it still said it was supposed to send me a notification. I haven't changed the permission settings on the app and it still works I'd say the majority of the time; it's very weird.
My other guess when I first noticed it was that Doze was being too aggressive and causing it somehow but usually that manifests itself to me as notifications coming in much later than they were supposed to arrive once I pick the phone up and move around, not them just straight up not showing up.
Yeah, power saving setting is a good shout. I know my newer phone(s) are more likely to sleep deeper so it could be possible the Calendar app is not in the 'override sleep settings' group or similar.
I thought I must have accidentally opened the diary event and somehow fumble-changed it so it no longer had a notification attached the first time it happened, but then it worked fine the next day. It didn't work yesterday and I looked at the event and it still said it was supposed to send me a notification. I haven't changed the permission settings on the app and it still works I'd say the majority of the time; it's very weird.
My other guess when I first noticed it was that Doze was being too aggressive and causing it somehow but usually that manifests itself to me as notifications coming in much later than they were supposed to arrive once I pick the phone up and move around, not them just straight up not showing up.