Hey guys, I am running Android pie on OP6,t and I managed to get my ant+ device working by allowing the ANT Radio Service application access to ANT hardware.
To do this:
1. Go to Settings
2. Apps and Notification (then See all # apps)
3. Scroll to ANT Radio Service and click on it
3. Click on Permissions
4. Click on Additional permissions
5. Toggle use ANT hardware on
Before I did this ANT tester app said that my phone is ANT capable, but also said No service and no firmware version. After I enabled it, the no service message disappeared and it could figure out the firmware version.
I also noticed that I can only have one app actively tracking my heart rate data (the others would not be able to find the sensor, so keep that in mind).
I included some screenshots for clarification.
Hope it helps!