I just wanted to jump in to explain expected behavior on the website and the apps.
If you have an account set to simplified and you change it to traditional, any characters you’ve previously learned that don’t have any variations will remain learned on the deck level and will be due for review in the queue. Characters/words that have variants will be hidden from the due queue, and they’ll be ready to learn on the deck level (unless you learned them in the past). The same goes for when you’re going from traditional to simplified style.
If you go back and forth using this setting you can study simplified and traditional in batches, which it sounds like you’re doing @Procellis
On the website, we do give you the ability to either continue adding in the new style from your current state, or restart decks (and fill in the gaps). The reason for that is because the website needs to point to specific sections for item adding, and the default is to just keep adding from whatever section you’re currently on.
@kjkjkj if you’ve previously learned traditional stuff and then switched to simplified they’ll still show up as Jeremy mentioned depending on some old app settings. You should be able to override this here: https://legacy.skritter.com/account/settings-study by changing your study style on your account to just “simplified” rather than “simplified and previously added traditional”
Hope that’s helpful, and good luck on the HSK test!