VPP Sign In Now Opening iTunes, But Timing Out

I thought I was going crazy, this is also happening to me. I had a friend in a different district attempt it, but he's using Apple School Manager and didn't have any issues. I've not switched over to ASM yet, not sure if that's a commonality. Tried different browsers, different operating systems. Yesterday it wouldn't' launch itunes, even on the Mac, today it'll launch it, but stall out. It's baffling. I have to call Apple on a different issue today, I'll also ask about this and post what I hear back.

When does this comes up? I checked it on High Sierra Safari and I ended up in the portal to buy apps as usual. I use https://vpp.itunes.apple.com.

For me it comes after I've hit the final purchase button after first searching for the app, selecting the number I want, and hitting the confirm purchase button. The next button, the final "buy" is what then triggers the launch of iTunes.

Sounds like this is affecting some customers in our area, but not all. My VPP still looks normal, my ASM now has a "Get Started" button to migrate VPP into ASM.
From someone who opened a case "I've never seen this before":

... case number is 100364996485 if anyone would like to call in to report
the same issue, which will add weight to the request. The rep I was
working with said that he didn't know if it was just me or if other people
are experiencing this, but regardless he was going to submit it as a high
priority request. If anyone else affected calls in and piggybacks by
referencing that case number it's typically a pretty quick call to add a
"me too."

Also, I just read the following which had not occurred to me but I like it!

Writer was a jamf user named Christopher, thanks for the lightbulb moment!!

"We have been waiting for this update since we heard that it would let us off load (transfer) licenses between VPP accounts (tokens). We have large number of unneeded licenses and with Apple killing 32 but apps will have more that we cannot use. Being able to transfer them to a “junk” token is going to help with VPP performance (We use Jamf Pro)."

@Sandy Ha. We had the same idea. We were going to call it the "Graveyard" token.

@tsossong Thank you for the direct link. I just tried again now and it seems to be working OK now. I am not sure why this was happening, but perhaps it was fixed, or maybe I was using the wrong address. Not sure.

Thanks for all the feedback folks.