Dagbani tilde works well on all Wikis I have tried, except that on Meta, it only works for visual editor but not the source editor. Is this a known issue? ~~~~
Topic on Help talk:Extension:UniversalLanguageSelector/Input methods/dag-tilde
Do you have Syntax Highlighting enabled? Try disabling it by clicking the button between the puzzle piece and "Advanced" in the toolbar, and check whether it works.