The Android App v2.16(49) doesn’t upload data to the WF servers when connected to the hub with Bluetooth the internet with cellular data. This was tested with a Samsung Galaxy Tab E running Android 7.1.1 and a Samsung Galaxy S8+ running Android 8.0.0. Bluetooth upload works with an Apple iPad Mini 2 on iOS, though it is quite slow (one time / minute?). @dsj, is this still on the roadmap to be fixed in a future update?
I finally just setup the hotspot on my iPad and updated the hub accordingly.