Purchase opt on Stock doesn't stay with PR Project file – after log out from one account to another

Hi all – 

Logged in to my personal account, I created a PR project using (watermarked) Adobe HD video clips. Now that I wish to purchase the clips, I want to purchase them using someone else's (my client) CC account. So, I log out of my account, and log in to his and load the PR project again. The clips are there of course but the option (shopping cart icon) to purchase directly from within the PR project is not there.

I thought I'd be clever and log into his Adobe Stock account while still being logged into my Adobe CC account. Nope. You can do it oddly enough but it just purchased using my Adobe Stock account. It didn't care who's Stock account the machine was logged in to. I've also tried to export my Stock library but there's no way to import it into another account that I can see.

Ultimately I could search for all 26 clips again while logged into his account(s), purchase them, then hopefully be able to Replace Media from Bin. But I was hoping it would be easier.

So, any thoughts on relinking (the purchase option) of Adobe Stock clips/library after logging out of one CC account and in to another – using the same PR project and same Adobe Stock clips that carry over?

Thanks

-J