I also lost one legendary card for each class, and one legendary card appeared that I didn’t create, the question is where to write to deal with it?
I believe this is because of the Core set.
Do you know what the Core set is?
Yes, sounds like the affected cards belong to the core set.
https://hearthstone.wiki.gg/wiki/Core
The core set is changed once a year. Those cards do not belong to you. They are loaned to each player for a year.
Look at this picture and you might find the missing cards on the left side. On the right side are the cards the old ones got replaced with.
https://bnetcmsus-a.akamaihd.net/cms/content_folder_media/N68NFIECFYBX1707418383158.png
Yes I just know and remember that I had these cards + another appeared that I did not create there are not a total of 9 legendary cards per class