I have this funny spike in pricing between 22:00 and 7:30 though switched to dynamic. It funny enough is equal to the peak-price period I set when the contract type was "Fixed".
So I suspect some data resides in the table from the old settings.
It is rather inconvenient, as it makes the graph very hard to read, (but that is a minor inconvenience compared to the scenario in which ESS decides to empty my batteries every night in the illusion of making me rich :-)