I'm using the plugin Redactor Extras https://github.com/elliotlewis/Redactor-Extras as I need be able to insert IDs to then anchor link to them.
However I'm finding the plugin adds the IDs as it should but on save they get stripped out. Oddly this plugin also allows you to add Classes which seems to be working but is still a bit temperamental.
Are there any settings I could try for Redactor to stop it doing this?