2 ways to solve this:
1: plug your original phone charger into 230V and its USB-C into the multiport. Connect your phone to the multiport. It will charge (not as fast as if you directly charged the phone). 4 hours from 30% to full.
2: connect the Samsung Galaxy S10e to the multiport and place it on a wireless charger (15W). 2 hours from 30% to full.
I tried this also by surfing the web using the monitor, sending an email and talking on the phone via bluetooth headset at the same time. The wireless charger was still adding more juice to the phone's battery than I was draining.