No you aren’t doing anything wrong. Just to check, you’re using the same “location” to add your locks, i.e. you can see both your locks at the same time in the ST app. Since you’ve already tried to exclude and re add your lock then the next thing to try is to uninstall and reinstall the guest lock app.
If that doesn’t work you may want to contact ST support or look into another app like LUM to manage your locks, users, notifications and actions.