All of this depends on what you did before the summer began. Quality, variety, recovery, nutrition, etc. all matter.
If you ran 40-50 miles per week all at the same pace that's a mistake.
Also race strategy matters. Plus once you have overtrained it can take a lot of time to get back to where you where.
Bill Bowerman made one of his top runners drop to three mile runs daily. He had teammates spying on the guy to make
sure he never did more than three mile runs. After a month he dropped his two mile time by a minute.
Consistency is important, but that does not tell the whole picture. You must also have reasonable progression and
some logic to your training. Did you work on speed during the summer...