I was using 2 ports of the Anker 40W 5 port charger. 3 ports unused. I moved one of the charge inputs to a separate wall charger and then both charge inputs were at 2 A! So the issue isn’t the Power Core, but rather the Anker 40W charger.
In that case give this a try for the 5 port charger: If a port isn’t working properly, it may be because your device has triggered the protective internal safety switch. In order to reset the switch, unplug all cables (including power cable) for five seconds and retry.