I've noticed something: I used my Helix offline, away from home, with the group, and now, back home, the time changes about 5 seconds before my computer or phone.
If I change the time manually and then back to automatic time with an internet connection, it's still about 5 seconds ahead.
The first time I used my Helix, I couldn't log into my account, and it was due to a known bug: the time wasn't correct, even with an internet connection. I had to update it manually and then switch back to automatic. I don't know if this problem is similar...