DFR0559 Solar Power manager

Hi,
I’m using the DFR0559 5V solar power manager along with the Waveshare 6V, 5W solar panel to power an esp32 board and to charge a 3.7V Li-Ion battery (7800mAh). I monitor the current/voltage delivered by the solar panel with an ina219 board. The problem is that the measured current never exceeds 410mA (max power of about 2.8W) in sunny conditions, whatever the orientation of the solar panel…