From the above mentioned handbook ..
"Switching to EV drive mode when the gasoline engine is cold
If the hybrid system is started while the gasoline engine is cold, the gasoline engine
will start automatically in order to warm up. In this case, you will become unable to
switch to EV drive mode
To prevent gasoline engine warm up in order
to reduce noises, start the hybrid system without starting the gasoline engine, pressing the
power switch with fully depressing the brake
pedal and pressing the EV drive mode switch."
This is slightly different from the process in my RC, where one puts the car into the Ready state and then presses the EV mode switch. This 2019 RC model waits a considerably longer period of time before starting the gasoline engine compared with the 2016 model