i'm facing nearly same problem but on a deeper look i found, i can upload 240p video but can't upload 580p means i'm not able to upload HD video and i tried 864x480p which was also not getting upload. My video size was for 580p was 38MB and for 240p is 6MB.
On the other hand, uploading snap during or before or after uploading video does not matter because my 240p video is uploaded after snap.
If someone really have any solution to this and has uploaded HD video recently, please share the process.