My wife and I both have VS5s, bought 2 months apart (Dec 2023 and Jan 2024)
When we go for a walk, we find that the lap counter and step counts are off. Sometimes her VS5 says 1 lap complete (1 km) before mine and sometimes the reverse when we've both walked the same distance in the same time. The difference in timing can be by a minute or so.
At the end of the walk, the overall difference in distance can be like .3 km. I know that there is some variation in our path, but not that much.
Both phones (hers Samsung; mine Pixel 6 Pro) have GPS turned on.
What's also interesting is that the map of the walk mostly shows the correct direction, but off laterally by a couple of meters. So that it doesn't show us walking on the road but beside it and in some cases walking in a pond.
There was also a case where it showed I completed the first lap in 8 minutes (usually its around 10) while she hadn't completed a lap and then my second lap was completed in 3 minutes when I had only walked about 20 m.
Are these known issues?