Limited Edition Challenges
I’ve completed the criteria for the last 2 limited edition challenges, waited the 9 days and haven’t received either of the badges. Both phone and watch are up to date and connected to wifi.
Apple Watch Series 3, watchOS 7
Some people have found, in the past, that restarting the watch & paired iPhone have helped speedup the process:
How to restart your Apple Watch - Apple Support
Restart your iPhone - Apple Support