I arrived in HCMC on 4/22. Some things I learned processing through immigration.
1. I flew from USA via Singapore Airlines. No issues transiting through Singapore to Vietnam
2. After deplaning the first step is getting through transit clearance with a Health certificate. I didn't have one. There is an app from Ministry of Health that has to be completed. A bit complex if first time completing it. Need hotel information, addresses, provinces, and some questions I could not answer. There was an official there who assisted me (and about 15 others who also did not have it). When completed I showed it to the official with my COVID RT-PCR document. Got stamped and moved to immigration.
3. Waited in line only to discover I'm in the wrong line. If you need a Visa on Arrival. Go directly to the Visa issuing area - not the immigration check.
4. To get the visa, I had to completed an application. And provide a photo. I had issues because I didn't have the address and company information of my sponsor. Several people were also filling out the application there. However, I spoke to a couple of people who had completed forms with photo attached (even typed written). Here lies the difference in sponsors. Who also told me he didn't know I needed a photo. Hah! I always carry extras when traveling.
5. Finally got that done with the help of visa official and paid $25 US and was issues a visa.
6. Then processed to the immigration checkpoint, process through with the additional sponsor documents and got my luggage.
7. I was met by my driver, changed into my PPE. I was the only one on a 30 passenger bus, and now in my small hotel room.
My point here is to ensure you have everything completed before entering. My agent told me it's very easy - just follow the immigration personnel. That's a JOKE.
Hopefully this was helpful.