Welcome to the forum!
No, you clearly have at least one place, maybe 2 or more, where the nodes aren't connected. Zoom into the area where the missing fill meets the path, and you can find them. To fix, select 2 end nodes, and click Join selected nodes button on the Node tool control bar
You might be able to fix one place, and solve the fill problem, without fixing the other (if there's only 2 places). But ideally it would be better to fix all.
Also I notice you've got hundreds, if not thousands of nodes in some of those paths. The Pencil tool is famous for doing that. I would suggest learning how to use the Pen/Bezier tool, because you set the nodes yourself, and can't get this exhorbitant amount of nodes. It's really not too hard. I made an explanation of the basic features in this tutorial (you only need to read that section, not the whole thing)
https://forum.inkscapecommunity.com/index.php?action=articles;sa=view;article=7But for now, you can reduce the number of nodes by clicking Path menu > Simply, once. If you do it only once you probably will not notice any changes to the path. More than once, and it will start to be distorted.
Or if you can't seem to find them, you could share your SVG file, and we can find for you.
That tutorial I mentioned will tell you how to avoid it happening. It tells how to close the path while you are drawing it, so you don't have to come back and do it later.
