Hi. I have Forerunner 945. I use Garmin Connect app to sync the device. To see the activity in Explore, I have sync with Explore app again. It souldn’t do automatically? I use the same account in tow.
The way it's working for you is by design. Your activities recorded on the watch will sync automatically to Connect App, but you do have to trigger a sync in Explore App on the Devices tab for the activities to sync to Explore App. This article has some more info about what syncs to Explore App: Items that Sync Through the Garmin Explore App