Trying to Set up SlimmeLezer+ on an Iskra AM550 in Bahrain

I live in Bahrain. My energy company uses Iskra AM550. I was well aware buying the SlimmeLezer+ was but an experiment that might or might not bear fruit.
So, I was able to turn on the SlimmeLezer+ using a USB charger, connected it to HA, all went well. However, upon connecting it to the Iskra AM550, it doesn’t power up. It doesn’t appear on the Wi-Fi network or HA, so basically it wasn’t drawing any power through the RJ-12 port. As a last ditch effort, I supplied it with power through the USB-C port while connecting it to the P1 port. The result is that it comes online, but provides no readings.
Question is: are there any other tricks I should try?