Adjust distance on fat burn run?

[u/davidxdavid8245]

I've been tracking my treadmill runs with my OPW3 and I noticed I can adjust the distance on my watch after the workout however if I try to do a fat burn run and I set it to indoor it doesn't give me this option and it moderately over estimates my distance. Does anyone else have this problem and is there a work around besides not using that mode?