Software updated automatically to 7.80 and GPS software version to 5.30 during the night and had a wrong signal for my whole run, usually even if it’s a bad signal --> it corrects itself during the run.
Somehow I ended with few “New records” on Strava.
Wish I was able to run this fast with a baby stroller.
looks like Strava doesn't recognize your 400m world record 
After every firmware update, as soon as the watch says everything has been installed, you always have to press the light button until the…
DO the usual stuff: soft reset (recommend after every update), then "soak" the GPS by leaving it outside for 15 minutes with activity ready.
If this will not help: use the forum.
looks like Strava doesn't recognize your 400m world record
After every firmware update, as soon as the watch says everything has been installed, you always have to press the light button until the watch switches off (Soft Reset), the next time you restart the watch something will be installed again, because the messages that everything has been installed will appear again, don't know, if this is a bug himself, but with this i haven't any probs then!
