Purchasing the products to take your own photos and videos is a great idea! Ordering samples allowed me to have more content to post on Instagram and use for my storefront - it's awesome.
Now, in regards to your question. Normally, on Aliexpress you are purchasing them directly from Aliexpress.com. It actually doesn't interfere or use Oberlo at all. What was the Oberlo change you noticed? Additionally, are you still trying to order from Aliexpress.com or were you trying to order from your own store?
Once I have this information I can dig a little further to see what is going on!