The problem is that you may have a system sitting right next to the SMP, and images, instead of coming from the SMP (or worse, being captured to it), are being pulled/pushed across the WAN to a remote package server. Other packages might be pulling from the SMP, or not, but the DS images will not no matter what.
This used to work in DS 7.1.
This is actually working by design, mostly. To explain, we need to describe how Package Server logic works, AND explain that unlike DS 7.1, we now use package-server logic (we ignored it back then).
Whenever you need a package of any kind, the client goes to the NS and says "where can I find this?" The NS looks at it's vast store of ultimate knowledge and determines what package server "near" you can service that request, and sends you up to 10 package servers to try.
But there are rules around this process, as follows:
The last bullet seems to be our problem. DS seems to ignore that logic, and simply pulls any package server it can, OR possibly, it also may ignore site bondaries all-together. Full testing has not been done to verify this.
DS 7.1 didn't use Package Servers. It used Task Servers. Granted, package services were required, and package was often used for replication, but the KEY to DS 7.1 was task server. We connected to your task server and hoped and prayed the image was there. Since the SMP is a task server by default, it would be mapped to. You may recall that images captured OFF the SMP would not replicate back to the NS, but that is largely forgotten in light of this issue. The reason is that the SMP is NOT a package server by default.
And, now that we are appropriately (mostly) using Package Servers, the SMP is ONLY used as a fail-over/last resort.
As a general rule, it is a "Best Practice" - a well known one for several reasons including hierarchy - to make your first Package Server in the same location/site as the SMP.
If you do not already have one, get a site server near your SMP so you don't pull packages across the WAN.
The issue is being looked into by Development.