Fitness app isn't accurately recording exercise time

The last month or so my Fitness app has become less accurate when it comes to recording the length of time I am exercising. To be specific, the exercise ring function on the app. I've read some other questions about this issue and I have repeatedly done the suggestions around syncing my watch/phone/apps. So that's not the fix.

A few observations:

--The accuracy of the Fitness app decreases when I simultaneously listen to music or a Podcast while walking.

--The accuracy also tends to fall off when I walk the oval track at my local high school. For example, the first part of my walk - about an hour -- is through neighborhoods. I spent 30 additional minutes walking the track. The Fitness app usually only registers half that 30 minutes.

--The accuracy tends to be OK if I unlock my phone and keep the app running.

--The accuracy tends to be better when I carry my phone in the same hand that I use for my watch (versus tucking the phone into my jacket or using a shoulder harness)

What's odd is that the Workout app accurately reports the time. I can click through on the Fitness app and see that the workout is recorded correctly. But for some reason the ring function isn't picking it up.

The simple fix seems like a line of code that forces the Fitness app to register anything the Workout app records.