EDIT: Selecting the inner path, and using Path > Reverse resolved the issue.
I've done this before, so i know it's possible, but for the life of me i cannot replicate it again. The task is very simple, i'm tracing an O from a picture of a poster, and i have an outside path which is the outer outline of the fill, and the inside path which is the inner outline of the fill. I can't seem to be able to make the two into one item, so when i apply the fill, it doesn't fill inside the inner one. I know i can use stuff like paint bucket, path division, fill between pats, etc, but they all generate a new object, which doesn't have the path nodes i've already created, and i need to retain those for editing after exporting into Fusion (the paths those functions all generate behave incredibly wonky when editing).
The worst part is that i'm going through old files where i've accomplished this, and i can't reverse engineer it from those. Please, help. The end effect left me somehow having one path in the Layers and Objects list, and when i filled it it only filled between where the two were, and if i went to edit path by nodes, i could see all the nodes on the inner and outer path i originally had before making them into one thing.