Why are complications showing ----?

If complications on your watch face keep showing - - - - dashes and no content, please try restarting your Apple Watch. This is a bug introduced in watchOS 7.2 which is still present as of watchOS 9.4. It is unfortunately easy to prove as a bug in watchOS, using a watch with an always-on display, as the complication content will usually show up perfectly fine in the low-power state, but will show dashes when in the on-state. Restarting the watch, and then tapping the complication to allow the app to update the content, usually fixes the issue - but it will return. Some times within minutes - sometimes weeks. If the issue persists, please reach out to Apple Support and log a bug report.