If your washing machine is not washing as it used to, there are several possible causes you can check and try:

1. Detergent Amount: Check the amount of detergent you add to the washing machine. Using too much detergent can make clothes harder to clean and leave residue inside the machine. Start with a small amount of detergent and increase the amount if necessary.

2. Detergent Quality: The quality of the detergent is important. Low quality or old detergents may not provide effective cleaning. You can improve the results by using a quality detergent.

3. Water Hardness: The hardness of your water can affect the performance of your washing machine. Hard water can reduce the effectiveness of detergent and leave residue on laundry. You can reduce the hardness of your water by using water softeners or softeners.

4. Cleaning: Clean the inside and seals of the washing machine regularly. Limescale, detergent residue or dirt may adversely affect the performance of the machine. You can clean using machine cleaners or vinegar.

5. Filter Cleaning: Some washing machines have inlet filters or pump filters. If these filters are clogged, it can block water circulation and reduce cleaning performance. Clean or replace filters periodically.

6. Washing Program: Make sure you select the correct washing program. It is important to select the appropriate program according to the type of laundry and the degree of dirt. Long and high temperature programs should be preferred, especially for heavily soiled laundry.

7. Machine Maintenance: Perform periodic maintenance of your washing machine. Check and clean the seals, hoses and drum regularly. Also, have your machine checked by a service technician from time to time to ensure that it is working properly.

By following these steps, you can improve the performance of your washing machine and achieve more effective cleaning. However, if the problem persists, it may be necessary to consult a professional or call for service.