Org export filters only work in emacs27 and above apparently. Or maybe whichever version of org I have installed. At this point I just need to assume nothing works in emacs26 I guess.

config.org

@@ -486,11 +486,12 @@ Settings for export, fairly basic because the only thing I regularly export is H
 Export non-breaking spaces properly; from, believe it or not, [[https://orgmode.org/manual/Advanced-Export-Configuration.html][the Org Manual]].
 
 #+BEGIN_SRC emacs-lisp
-  (defun my-html-filter-nobreaks (text backend info)
-    (when (org-export-derived-backend-p backend 'html)
-      (replace-regexp-in-string " " " " text)))
-  (add-to-list 'org-export-filter-plain-text-functions
-               'my-html-filter-nobreaks)
+  (unless (version< emacs-version "27")
+    (defun my-html-filter-nobreaks (text backend info)
+      (when (org-export-derived-backend-p backend 'html)
+        (replace-regexp-in-string " " "&nbsp;" text)))
+    (add-to-list 'org-export-filter-plain-text-functions
+                 'my-html-filter-nobreaks))
 #+END_SRC
 
 *** Packages