Sorry to hear about these issues with you Apple Watch Series 2! We do have a few suggestions for you! We have an article addressing these types of issues: https://appletoolbox.com/2017/02/apple-watch-not-importing-syncing-contacts/
To sum up, since you’ve already tried a lot of options to fix the issue, it sounds like you need to unpair and the repair your Apple Watch.
If you continue to experience problems, let us know or contact Apple Support. AppleToolBox is not owned by Apple, so if you want to reach Apple Support directly about your problems with your Apple Watch, please contact them here: https://support.apple.com/en-us/HT201232
Best of luck,