Keg beer is pasteurised so it shouldn’t be cloudy.
Check if your lines need cleaning, put on a new container and draw off two or three pints until you know that the new product is coming through, the beer should now be clear. .
Check again after about an hour. Draw off a pint, if the beer is now hazy, then it is almost certain you have yeast build up in your lines. This is causing the fresh beer to become infected, when left in the lines for any length of time. You may be cleaning the lines every week but are you adhering to the correct instructions.
If after an hour the beer is still clear, then you may have a faulty keg. Notify the brand owner, and they will check it for you.
You can check for yeast build up by getting a torch and shining it through the beer pipes. If a brown stain can be seen then you have yeast build up. You should contact your local Tech Services for advice.