I’ve created a checklist of reasons why the styles might not be showing outside of MT in the troubleshooting video. Number one is that you need to click the “Publish” button for changes to be visible to non-admins. See the green button at the top right of Microthemer.
You will also need to clear your cache after publishing.
Could that be the issue or any other shown in the video? Either way, I’m happy to provide further assistance with this.