After Long Break, Connect No Longer Syncing Steps (Forerunner 35)

After a long break I decided to dust off my Forerunner 35 but I am encountering an issue when it comes to syncing daily steps with the app or site.

In short, none of my steps (0), even though they are being counted by the watch (13K+ yesterday) will show in the app. All other activities (running, workouts) sync properly.

One issue that might be related is that the first run I did with the watch yesterday didn't establish a correct GPS liaison (I guess), and the activity was logged for a completely different date (in January 2017) even though the watch dispayed the correct date and time before, during and after the activity.

That issue is now fixed (proper GPS signal before activity is launched) but I wonder if maybe my daily steps are still being counted and logged for some day in January seven years ago.

Any ideas on how to fix this? Restarting the watch and phone didn't help.