twisting yarn

Making shawl witn cables on circular needles; my yarn keeps twisting, how to prevent?

Welcome!
Sometimes it’s the way the yarn is spun that causes twisting or sometimes untwisting. Best thing may be to periodically let the project dangle from the ball and untwist. You can also secure the working yarn to the ball with a spare needle to let the ball dangle and untwist. I haven’t tried a yarn Susan but it’s one suggestion here:

Thanks for the reply