I have hundreds of Adobe stock photos and use them frequently. My collections loaded into Creatice Clud Express (Spark) and all the photos are telling me to buy them. I can just as easily upload but why does it say this? I take care to follow usage rights, give credit, etc. so it's bothering me.
The first thing to check is that you are using the same Adobe ID. Try signing out, then sign back in again.
Since your question is about Adobe Stock, I have moved this from the Photoshop forum where you posted.
I don't see that you have an active Adobe Stock subscription under the email address you are using here on the forums however I do see that you have Creative Cloud Express. Please review https://helpx.adobe.com/express/express-faq.html to learn more about Adobe Stock and Creative Cloud Express.
If you have additional questions please post here.