If your slider lid is popping up when using it with a hot beverage, steam may be collecting under the lid. When this happens, steam is unable to escape and pressure builds causing the lid to pop up slightly. To alleviate this pressure, leave the slider on the lid open while attaching the lid to the cup so that the steam can escape. The insulation of your Swig will continue to keep your beverage nice and hot!
If you are still having issues with your lid, please reach out to us at firstname.lastname@example.org.