I've been using a Charge 5 for close to a year now. I'm actually on a warranty replacement, but I'm not sure if that is the cause of this. For the last couple weeks the Fitbit cannot accurately track laps during swimming. I'm in a standard 25 yard pool, and the tracker is set to that length. I'm swimming front crawl as is the recommended stroke for the best accuracy, and I execute a fairly passable flip turn every turn until I finish a set. I usually swim at least 10 laps on every set to ensure a good amount of data. However, it always undercounts laps by at least 10%. Today I swam two sets of 15 laps, then 6 more to round out a mile. It counted both of the first two sets as 13.5 laps (675 yards) and the last set as 5 (250 yards). That's pretty much a typical result for every swim in the last few weeks. It's a minor miracle if it actually gets it right. Particularly egregious to me is how it counts half laps (lengths) on my swim when I NEVER finish a set at the other end of the pool. Even if I'd somehow miscounted mentally, that much I can be sure I got right.
There needs to be a way to manually adjust lengths after the fact. I believe the PC app sort of has this ability, but the last time I tried it, it kept coming up with a value completely different from what I had entered. I had to keep adjusting it through trial and error to get anything close to the number I wanted.
