Yeah, the same thing happens to me. It seems to be triggered by opening the app. I’ve had it where opening the app causes about 15 minutes of data loss leading up to opening the app. Here’s where I first open the app and see there’s data loss:
I left the app for a few seconds and came back into it, and the data loss happened again (note that it still knew about where the fridge had turned on, but had lost the power meter data);
Half an hour later I came back again to see if maybe it would come back, but by then it had even forgotten that the fridge came on:
When it happens, I’ve lost about 15 minutes of power meter data, and everything shows up in “Other” for a few minutes until it has a chance to figure things out again.