Making flight plans available offline

I am working in a remote location in the Australian Outback with rare access to the internet. What internet access I can get is very slow and only about once a week, so I have limited opportunities to create new flight plans and download them for offline flying. I am flying a Mavic 2 drone with an Android phone.

I need advice on how to ensure my offline maps are actually there and ready to use. Although I was able to initially download a test map and fly it offline, every other map I have since created, despite telling me that it is available, appears to not be available when I try to fly. When I select Make Available Offline, I never seem to get the spinning arrows symbol or a report that dynamically shows the % download, etc. When I go to do the flight, I cannot get the flight checklist icon to show up - it always stays as the disk icon for saving a flight plan. I have sat with DroneDeploy open on my phone for 2-3 hours and I never get the % download or spinning arrows to show up, but the app still says my flight plan is available. Yet, when I try to fly, I cannot get to the flight checklist. Maybe there is something else that is keeping that checklist from showing up, but I can’t figure it out.

If anyone has ideas for how to ensure I have an offline map that is ready to go, prior to me being 2 hours from the nearest WiFi, I’d be grateful.