Daniel I can’t tell from your question if you’re tasks have assigned resources. If yes, here’s something to consider. Are the tasks with the task calendars set to ignore resource calendars? If not,the resource calendar could be restricting the amount of time a resource spends on the task. For example, if the task calendar indicates the task could be worked on M-F for 20 hours each day, but the resource calendar says the resource can only work 8 hours per day, the resource calendar will only allow the resource to be allocated to the task 8 hours a day, regardless of the task calendar. Checking the Ignore Resource Calendar option on the task tells project to disregard the resource constraints and schedule the task solely on the task calendar.