This is the second time in two years I've used this charger in Thailand. I've been very impressed with it so far, as it combines high performance, current standards (USB-C), and international compatibility. The only downside was its weight, which is typical for this GaN technology. According to the specifications, I could charge two phones simultaneously in PD mode, and the other two ports were for charging my cameras. This worked perfectly on my first trip. Then something happened on this current trip. My new DJI Action 4 isn't charging at all. The charging indicator keeps fluctuating. If I connect more than one device at a time, they seem to be trying to charge each other, as the battery indicators show them all discharging simultaneously. The PD function only works on one port. What used to work perfectly is now a huge disappointment. I'm now limited to a single port on vacation. I can only charge my Action 4 camera using a power bank.