Hi, thank you very much for sharing with us the inconveniences you have encountered with the sensors of the Apple Watch Series 11. It is important for us as it is for you to provide you with an exceptional customer service focused on giving you a smart watch that works perfectly fine without any significant inconveniences. If your watch is not tracking workouts, not showing heart rate, or not locking when removed verify that it fits your hand and it is not too loose, you can wipe the sensors placed on the back of the watch to double check that there is no interference, you can also check privacy settings Privacy > Motions and Fitness and ensure that this option is enabled. Additionally, you can pair and unpair the wearable or restart the watch completely to verify if the sensors start working afterwards. If none of the steps outlined above worked and you need a technical support specialist, you can contact Apple support at (800) 275-2273. Thank you for choosing AT&T!