It's just a coincidence ( here, you have the sample of just one test). Here, your season declined at the same time as one normally risk hitting a bad string of results due to lots if factors, like the ones below
- Bad wheather, your tactic not being suited for it
- Players getting complacent due to having had good results
- Players being tired due to you not rotating the squad
- Opponents equal or better than you now sits deeper and defend and your approach works less good against teams like this.
- When getting some poor results, you have not been able to turn things around
- Key players being out of form and due to bad results loosing out in morale
Etc, etc