Call the embassy where you submitted. The number should be at the bottom of the website. I applied in Hanoi. Also do a search for “Vietnam” in this group and you will find instructions left by some that had success with their applications. Good luck 🙏
Try calling the embassy for more info. I’m also wondering if a visa agent might be helpful for you to assist you with this. I’ve never used one before but they exist to make things easier for people. The number for the embassy in Hanoi is at the bottom of their website.