I asked a question about ship upgrading in Stellaris here and learned that ships will upgrade to the latest design or the latest design with their name. I'm now trying to upgrade ships of one class (call it Class A) to a new class (call it Class B). I have only created one new class, Class B, but the ships I currently have of that class will not properly upgrade, even if other ships in the fleet will upgrade to new classes properly.
Are there any reasons why this would be happening? How can I fix it?