Debug My Time Series Regression Model

I'm experiencing issues with a time series regression model. The model is not crashing, but its accuracy is lower than expected. I need an expert to diagnose the problem and suggest improvements.

Ideal candidates for this job should have:
- Extensive experience with regression models, particularly with time series data
- Proficiency in diagnosing model issues and improving model accuracy
- Strong skills in Python (or R), and experienced with libraries such as pandas, NumPy, scikit-learn, etc.