I just did this on a test account, and I can confirm that some words are getting marked as learned in addition to the single word/character. But not all. I’m unable to reproduce this with words you’ve never studied before on Skritter, so if you’re seeing that, then please reach out to team@skritter.com so we can investigate further.
To the best of my knowledge, this is an issue right now with how previously learned words are being handled when you jump position in the deck. It ends up marking some words as learned up to the next word item you’ve never studied.
We have an open issue for this, but the fix will actually be to make deck rejuvenation automatic, which will allow you to quickly study new words and items without having to spam “Mark as learned” or guess at how much of a deck you really know when you open it up for the first time.