what Its a glitch that's been happening for a lot of people, not just me or DD sadly - even after going through all those steps and trying uninstall/reinstall or disconnect/reconnect. Greenify has been DD and my friend for whenever we have PoGo off.
We've noticed there's also an issue with DDs phone and Google Fit not updating in the same way as my phone does, so as long as someone opens the Fit app and makes sure its updated itself it goes fine, but otherwise she loses kms. Bloody Android.