My steps are not accurate on my Garmin 645 watch face or in the Connect app over this week. My steps are only 1/5 of what they usually are and I haven’t changed my activity level.

Has anything else changed? For example. If you push a stroller or similar the step counting doesn't work so good, so if you went on parental leave recently that could be an explanation.

If I had the same issue I would start by checking the step graphs and see if I see something odd: https://connect.garmin.com/modern/daily-summary/2020-12-12/steps (switch day with the arrows at top and check the other days)

Compare with days when the step counter was working as it should. Are there anything that stands out.

I would also check the step counter on the watch. View the step counter widget (not the watchface since watchfaces might have delays for the data) and simulate 10 steps by moving your arm up and down. After 10 "steps" it should count 10 steps. If you are still for about 3 seconds you will have to restart the step counter by doing 10 more steps.

The standard problem solving techniques should also always be done before anything else:

• Connect watch to Garmin Express and check for updates and do a sync that way.
• Restart watch.
• Restart phone (probably not necessary for this issue since it is the watch that got the issue)