I can think on why it’s happening. It’s because the amount paid for the bundle is lower than needed. The change from a few weeks ago made the weird things you mention because it happens when the current price of individual files are higher than the amount paid from before. At least, that’s what it says the Itchio docs.
Don´t worry though. Send me an email to “hello@shackhal.com” with a proof that is you (like an image, showing your username, the bundle in the library and the assets from its search) and I’ll send you a new key.
Take care.