Some themes and apps do not support custom currency formats.
The app would not work when using these:
* SectionHub Page Builder
* Dynamic Product Options
* PageFly ajax cart
* Frequently Bought Together
* Language apps like WeGlot / Langify / etc.
* GemPages (you can contact their team and request for an integration)
* Themes by troopthemes.com - will show formatting code inside product pages.