You should still try increasing the budget to $400+ and keep increasing it if things are working out. I'm pretty sure Facebook spends your funds evenly over the day sometimes. So if it is early morning and it sees that it has already spent 15% of your limit then it might stop. uhh I'm not completely sure if it does this with individual campaigns, but it did it with the account daily spending limit the last time I had a lower limit. I remember it would spend a bunch of money and then stop and then it would hit the daily spend limit perfectly at midnight pst.
Facebook will also spend your campaign budget evenly over the day.
desiat, run the campaign for a full 24 hours without touching it at all. See if it hits your campaign budget then.