I don't think cooking time or temperature is your problem. I've had
this problem from time to time (and continue to have it from time to time).
The most important factors are correct liquid to flour ratio, temperature of
ingredients, and freshness of the yeast. Humidity is also a big factor but
requires more guesswork than the others. There are guidelines in the recipe
booklet for alterations to the ingredients to compensate for different
humidity conditions. I've found that if the setup is done properly, the dough
will rise properly and not look like a little bowling ball just prior to
baking. Then the loaf cooks properly and is done in the center.
I takes some practice. We still screw up every now and then,
particularly with new or complex recipes. One little trick that's worked for
us is to add a little more liquid and a little more yeast than what is called
for in the recipe to "get a rise" out of your dough.
Good luck and don't give up!
/sdd