Yes, it’s started at 23:00 as it said.
I’ve not really had many problems with charging using the Ohme App, I did notice that when I plugged it in about 3pm ready for tonight it came up with about 10 charging slots of 1 to 2 minutes each from 3pm onwards. Usually, as you say, they’re 15min slots.
Just in case it was getting confused with the new times being applied tonight/tomorrow I unplugged it and plugged back in at 7pm, that then gave the more sensible times I posted above starting at 23:00.
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!