I have this same issue, not sure how to get it to sort correctly. Luckily its not that important because its only showing whats for dinner the current week and my data has Monday - , Tuesday - in front of it so I can still see its just out of order most of the time.
It gets worse when you use the urgency flag with an absolute configuration. The urgency flag changes some of the events to relative times while leaving the rest to absolute. So it might say an event is in 3 days, but when I look at the absolute date, in my mind, it’s 4 days away. It’s simply how we count from an arbitrary time frame versus how a computer counts from a fixed point, that being midnight. The joys of programming.