The war resources they accumulated during the previous hibernation phase are their last reserves.
Now, even though they have regrouped and reappeared, in the process of attacking the Western Front Army in Salius, they have regained control over many worlds. However, the supplies they can obtain from there are not enough.
There are some resources, but not many.
Insect infection has repeatedly spread over the past few years, causing enormous damage to living conditions. Moreover, the troops of Salius also need supplies, and during the previous war, they didn't spare any effort in extracting resources from local areas.
After several rounds, there is no longer sufficient profit to extract.
They do have one option, which is to continue retreating westward, moving into the Magrey Cosmic Domain to requisition resources locally.