... 1.5 A per charging port on 3 specific "charging ports".
Typically, a dedicated "charging port" doesn't carry data. I'm surprised you're getting anything out of it if you're plugged into one of those.
So... it's turned to 3 o'clock, I'm running at 100 MHz and on a port with 1.5 A... and it's giving me a reliable 2.865 GH/s on average something happened, and it popped up to ~10 GH/s...
But that's where it should be at 100 MHz. Still surprised you're getting anything out of a "charging port" but happy you're on track now.