The new iMovie doesn't seen to have an option "Share as App Preview", so I just exported it as a file and scaled to size 1080x1920 with avidemux (codec MPEG AVC, MP4v2 Muxer). Checking the format: codec H264, duration 29sec, 30fps — just as required for App Preview.
Uploading to AppStoreConnect with Safari browser as App Preview for 5.5" iPhone, I get no complaints and even can see some frames while uploading. However, after the upload is complete, a cloud icon appears instead of the video. After I refresh the page, the cloud icon turns into exclamation mark(!).
Also tried uploading 1920x1080 image for macOS — same result.
Searched on the web — couldn't find any meaning of a cloud icon for App Preview video.
Uploading to AppStoreConnect with Safari browser as App Preview for 5.5" iPhone, I get no complaints and even can see some frames while uploading. However, after the upload is complete, a cloud icon appears instead of the video. After I refresh the page, the cloud icon turns into exclamation mark(!).
Also tried uploading 1920x1080 image for macOS — same result.
Searched on the web — couldn't find any meaning of a cloud icon for App Preview video.