If you built the theme, I’d think you’d know if you did something to strip HTML tags out of titles. That is, unless you’ve imported code from elsewhere without fully understanding what it does. No judgement here, it’s what some people do. Otherwise it’s likely due to one of your plugins.
Either way, you’d need to find where the tag removal is being done. If you can find it, there’s a chance you’d be able cleanly override the removal. Of course, if found, you could simply remove the offending code. Editing source code is not the best option because you’d need to redo the same edit after every update. Ideally there’d be some sort of filter callback or something where you could use remove_filter()
without editing the original source code.
Finding where the removal is done can be a challenge. Narrow down where to look like I descried earlier. If you’re lucky, removal is done with something obvious like wp_strip_all_tags()
. But removal could be accomplished any number of ways, preg_replace()
for example.