After I got the quest to talk to Foreman Flatfinger in Sinfall, the quest text said to “talk to Foreman Flatfinger” which usually means to choose the dialog option first in order to be able to turn in the quest, so when I talked to him, I selected the “show me the sanctum” option. I had some anima in my bags from the 3 world quests, so I clicked “deposit” and my anima total increased to 580. Then, I talked to him again to complete the quest. The follow-up quest asked me to deposit 500 anima into the sanctum. I was worried that I missed my chance to complete the quest because it had already let me deposit what was in my bag. Fortunately, it seems to have given me credit for my previous deposit, and I was able to immediately complete the quest.
Here’s where the issue comes in - after completing the quest, my total dropped to 455, making it impossible to complete the next quest without farming more anima. 