@Mario3845
I don't think Hosts have the abiiity to bold or underline text in Scheduled Messages and Quick Replies (although we have been asking for that for years). Maybe somebody figured out how to do it though. If it appears you see bolded text, are you using the App to create the message? I understand that many Hosts have difficulty creating Scheduled Messages and Quick Replies in the App and the short codes don't work properly in the App.
I suggest you create all your Scheduled Messages and Quick Replies on a desktop/laptop and not in the App. To "test" how a message actually appears to a guest and ensure your short codes work properly you can send a message to your Co-Host using whatever message you have setup and you'll see how they appear. You can also go to a message thread with a guest and choose the message you want to view how it appears, just don't hit the send button.