I’ve made the changes suggested for 背が高い, you should be able to see the changes once you log out and log in again.
Also, about your issue of not being able to see the old courses; that is a new and rare bug that we have been struggling to get information from!! Your user case is super valuable, do you mind messaging me privately your user ID so that we can look at what’s happening to your account?
I could send you the course link now, but once you open that link, the bug of that course not being in your account will be resolved and we won’t be able to track the bug… so I’m definitely being selfish here by not giving you the link. If you rather have the access back than us, just let me know and I’ll send you the link immediately.