Base_path not being substituted in some cases

I’m not sure when this started, but it seems like %{base_path} isn’t being substituted in some instances.

The only place that I’ve seen this so far is the report a post prompt, where the url has the topic id replaced with %%7Bbase_path%7D/guidelines so becomes

I tested and verified that this also happens in safe mode.

The text of post_action_types.inappropriate.description is the default:

This post contains content that a reasonable person would consider offensive, abusive, to be hateful conduct or a violation of <a href="%{base_path}/guidelines">our community guidelines</a>.

I tested changing the text while keeping the link the same. The changes do appear, but the issue is still there.

I checked another instance of %{base_path}, specifically site_settings.tags_listed_by_group which does appear to substitute correctly. The tags listed by group site setting does have a working link in the description.