Hello,
I don’t know if this relates to this issue but I was in GMT-04 during these winter holidays, phone set to local time.
When I looked at the graphs on my phone connected via VPN to my home, I saw the graphs in GMT-04, i.e. with a 5-hour offset compared to the Gladys at home.
The 3000W spike in the photo corresponds to the water heater starting at 22:00 but shows a start at 17:00 
I wanted to make a dedicated post on my return but seeing @lmilcent’s last reply I think it might be related.