The current method of loading custom theme CSS files (via sjrk.storyTelling.loadCustomThemeFiles) can potentially lead to a race condition. The files are loaded via a call to [$.getScript|https://api.jquery.com/jQuery.getScript/], which will call its "success" callback after the script is loaded but not necessarily executed. The time between this loading and execution could therefore cause problems.
Look into how probable and/or possible this race condition is, and address it accordingly.
For further context on this issue, please refer to the discussion in the pull request review for