I too have tried the volt/amp meter on the routers. On a 3A power supply, the phone by itself will draw around 1.3-1.9A, so mine’s getting somewhere around 6.5W up to 10.
Into the router, depending on the cable, I can get anywhere from about .48A, which won’t even boot the router, up to about 1.1A. I haven’t seen it draw over 7W, but either way, it’s appears it’s not passing enough to the phone.
On the OTHER side of the router, the most I’ve seen out of the router is .4A, so 2W, and the current drops to .17 very quickly less than 1W, and then to zero.
If you have the phone set up to stay on as long as it’s connected, as the instructions say to, there’s no way the router is going to keep it charged.