Can you post a screenshot of what the app is saying? Have you Notifications turned off or DND on (just guessing)
When does it say there's a conflict?
Do you get the Agree to Exposure Notifications screen, the explanation, you agree and then Bluetooth comes on and it starts scanning.
I reinstalled it on my Motorola with Android 9, and it works fine also on my Nokia on Android 10.
Weird that it doesn't tell you what you need to do, but then nothing surprises me in 2020.
There are only reports of test result upload failures. The first answered review on the Play Store gives a typed link to an faq and answers page.
Sorry, don't know what else.