Why is my milage suddenly not tracking even though its on.

I have some steps and details to fix the mileage tracking issue you encounter in QuickBooks Online, Cheshireca. 

We'll need to check if the auto-tracking is on in the QBO mobile app when confirm, I suggest checking the device's location. Here's how: 

1. Open Settings.
2. Tap Location.
3. Turn Use location on or off.

I am sharing this article to review the other steps for fixing the mileage.

Moreover, here's an article to assist you in reimbursing mileage to your employees: Reimburse employees' mileage and vehicle expenses in QuickBooks Online.

If you still have other concerns about your mileage, don't hesitate to leave a comment below. Have a great day, and take care.