Trimmer head isn't spinning properly on a Stihl Trimmer

Links to products I have in my tool bag. Compression tester. https://amzn.to/2NMgeze Spark Checker. https://amzn.to/3bnXjmA Carb Adjustment tools. https://amzn.to/3k7cgxe Primer Bulb. https://amzn.to/3bwLLxj Fuel Filter. https://amzn.to/3dCKasx Chemical squirt bottle. https://amzn.to/3eWcGVs Above are affiliate links which means we receive a percentage of the revenue made from purchasing products via those links. Thanks for watching. This Trimmer starts and runs but the trimmer head isn't spinning like it's supposed to.