The Samsung tech via chat told me to take it in to an Samsung Service Center. They first tried to force the update somehow and that didn't take. Then they tried to do a "deep" factory restore and that didn't affect the current version which was still Jan. 2019 security patch. It did totally wipe everything off my phone and took me hours to get back up to usable and yet without any improvement so I could update to the current patch. They told me that if that didn't work, there was an error with my motherboard and since I was 5 days past my warranty, I would have to buy and pay to install a new motherboard. Something about the part of the motherboard that stores, holds new updates was likely broken. Yeah, I don't know about that. I have an unlocked Galaxy S9 on Tmobile. Is anyone on another carrier having this problem?
As an update to my original post: after chatting with Samsung tech support and them sending me to a local Samsung service center, (ubreakifix) who tried unsuccessfully to use some kind of "fancy" factory data restore, I ended up with a phone I had to reinstall everything on and yet I was still at the January security update--plus they said, it must be your motherboard then and we'll have to replace it. I called TMobile and their Tech support rep assured me, "after talking to other reps" that it must be a problem with Samsung and that there was nothing they could do and that they had never even heard of the problem. So, eventually, after waiting months with no update from January 1 on T-Mobile, I got a sprint sim and put it in. Within seconds, it found the latest upgrade and is updating my phone to the June Security update as I type. Yay! Though, what the heck, Tmobile?! How come every other carrier can make these updates available to unlocked S9 phones and you can't. Not only that, you can't get off your behinds to be honest with your loyal customers and help them out.