Article written on 2022 and applies to x10 systems.
If recorded video cannot be downloaded/viewed from the Luma app, the following solution should be followed.
It may be possible to see that the recordings are there when the NVR is accessed prior to this change and the app will report 'No Record Files'.
On the NVR settings under storage schedule there is a setting you need enabled to be able to view the recordings on the Luma app. You have to do this for each camera – under the advanced button you can select a stream type. This needs to be set to double stream so that the NVR records the sub stream as well as the main stream which is a lower resolution that the phone app can deal with and display. As soon as this setting is changed you can see the recordings.