Parkside hydrophore 1300 A1 - mode management with wireless relay

Hi,
I have a conundrum, I'm afraid there is no way around it with the equipment I have, but he who asks never wanders.
I have a wireless relay with remote control (as for the gate - on/off) and a Parkside 1300 A1 hydrophore for the garden irrigation system.
The hydrophore supposedly has three modes of operation:
- timer on: we are not interested in this because it does not want a fixed time setting
- automatic on (switched on manually with the "mode" button, which has safety features for dry running etc.), needs to be switched on and off each time with the button
- always on: works continuously without safety features.
I would like to use this last mode, but the connection does not work, because cutting off the power with the switch after causes the hydrophore to return to the initial setting, and you still have to manually turn on the hydrophore....
Hydrophore new, so I would rather not take it apart?
Can you see any options for getting around this? .

There is no way to do this without interfering with the electronics.