Hello SweetLazyJ,
Restarting your devices is a great first step to take, so thanks for doing that. We'd also advise that you check that both your devices are not on a beta software version and are fully updated. Follow these steps:
After that, if you've restarted, updated and re-paired your iPhone and Apple Watch and the issue persists, further assistance may be needed. We want to make sure you reach the right team for help with your watch and Challenge, so we recommend that you contact Apple Support directly. Depending on your region, you may be able to reach them here: Get Support.
Thank you for participating in the Apple Support Communities and have a wonderful day.