In Settings, Test says "API key not valid" although my key works elsewhere. What is wrong?

In versions before 1.9.14 the Test button checked the key that was already saved, not the one in the field. If you pasted a new key and clicked Test without clicking Save first, BookyAI tested the old key. Click Save, then Test. From version 1.9.14, Test saves the key in the field first and then checks it, and a field that holds a key that is not saved yet says so. "Connected" next to a provider only means that a key is stored, not that it is valid; Test is what checks it.