Assigning IAPs to to an existing AppLab release is not possible.

I cannot download the assets  because their "iap_status" is "not_entitled" when quering via the OVRPlatform plugin. See the JSON response below when quering for available IAPs from the headset, and notice the difference between the "iap_status". Setting the IAP price to "Free" via the Release page, is the only way I found to change this "iap_status", and I am unable to do so currently.

Attempting to download the IAP by it's id yields the following error in the logs:

Task(/storage/emulated/0/Android/obb/jp.co.Casaliz.Nanakoro/DLC_ShibauraNanakoro-Android_ASTC.pak) for Job(jp.co.Casaliz.Nanakoro|4b551c50-df81-4e46-a7fe-6b07c945066c) encountered exceptional status: DownloadBinaryNotFound

I would like to find out how to change this iap_status to Free through the dev dashboard or any other way. When an IAP was configured as "Free" in the Add-Ons dashboard, why do I need to additionally set all IAPs to "Free" on the Release page again, just in order to be able to download it from inside the app? I have to do this for every single app release and it's rather inconvenient.

{
    "asset_id": "6915533841814852",
    "asset_name": "DLC_ShibauraNanakoro-Android_ASTC.pak",
    "metadata": "",
    "filepath": "\/storage\/emulated\/0\/Android\/obb\/jp.co.Casaliz.Nanakoro\/DLC_ShibauraNanakoro-Android_ASTC.pak",
    "iap_status": "not_entitled",
    "asset_type": "default",
    "download_status": "available",
    "language": null
},
{
    "asset_id": "6869369503097953",
    "asset_name": "DLC_HarvestKyotoNanakoro-Android_ASTC.pak",
    "metadata": "",
    "filepath": "\/storage\/emulated\/0\/Android\/obb\/jp.co.Casaliz.Nanakoro\/DLC_HarvestKyotoNanakoro-Android_ASTC.pak",
    "iap_status": "free",
    "asset_type": "default",
    "download_status": "available",
    "language": null
},