@Jeff_Tyzack and @Mattias_Hellgren
You may have to disconnect / reconnect Zwift to Strava. Strava had a server outage earlier this month. Here’s how.
Re: Garmin It wouldn’t hurt to do the same for them too.
Note: this will sync future activities moving forward. It will not sync activities in the past. For those, you can download your FIT files and manually upload them to Strava or Garmin.