I'm not so sure that this is an indication of anything being too badly wrong.
Correct me if I'm wrong, but my understanding is that you've been lifting the watch (after a period of not wearing it and it not running) setting the time and simply wearing it all day, without manually winding it at the start. Then it continues to run for about 6 hours after you take it off. If that's the case I would say that there is nothing too seriously amiss. Obviously if 'all day' is roughly 12 hours, with 'all night' being roughly the same, a build up of 6 hours reserve each day is not enough to keep it going in perpetuity, but don't forget, the Cal 1045 only winds in one direction so won't build up a power reserve at the same rate as other watches that wind in both directions.
If you manually wind it at the beginning, then wear it all day, it should not need to be manually wound again, if you continue to wear it daily. If that proves to not be the case then it isn't performing as it should but nothing to get stressed about.