Ive spoke to apple online and they said that ive got to see if it still does it with the charger in and nothing plugged in but as Boisb has said it could be that issue with the board.
Ill also try this other thing but the henge dock was plugged into the right earlier and the USB-C SSD was in the left. Ive currently got the Henge plugged into the left and the drive into the henge and its still at 100%
Depending on exactly which model dock you have and how it's implemented, it's possible that the connection between the dock and the computer are limited to 60W, whereas the dock gets a full 87W from the laptop charger. If computer+SSD need more than 60W, it'll drain the battery.
Ive spoke to apple online and they said that ive got to see if it still does it with the charger in and nothing plugged in but as Boisb has said it could be that issue with the board.
Ill also try this other thing but the henge dock was plugged into the right earlier and the USB-C SSD was in the left. Ive currently got the Henge plugged into the left and the drive into the henge and its still at 100%