The strings are wound under the tension that they will be tuned to. That depends on their design. The heavier the string, the more tension is needed to pull it to pitch. Light gauge strings = less tension.
You have an AFB-200. It has a TAILPIECE. The strings do not start at the bridge they start at least 2 or 2 inches behind the bridge. That is why the longer strings fit, although the 324s would fit better. While your scale of bridge to nut is 30" you actually need MEDIUM SCALE strings. My Hofner bass is the same - it needs Medium Scale string The measurement that is important is ball to nut. Your guitar from the string ball to the nut is at least 32-33" On my 30" Mustang it is 31". for example.
And - I would not assume that the makers would put wrongs scale strings on their instruments. They will order the correct strings and use them to make the instrument sound as good as possible. Especially the low cost instruments. Please keep in mind that they make hundreds or thousands of these at one time, so proper length strings are not a cost item for them.