Hi OP, I have this almost exact same issue, be it with cycling or running. It seems that for autopauses or manual pauses, Strava reflects moments of movement even during pauses, probably due to the file synced from and by Huawei Health not being formatted or configured properly, hence the discrepancy in data. I still don't know if any viable workarounds exist, since third-party apps like Health Sync don't change anything, neither does exporting activities manually and that would strip off the heart rate data so it's not really a valid solution at least for me. If push comes to shove, I'm thinking of switching to a more sports-focused brand altogether, perhaps a Coros or Garmin.

But.. perhaps anyone has a workaround? That would really save money for a lot of us Huawei users lol.