Hello @YO3HJV
glad to hear you figured it out.
I was just setting up a test to see if I get this 400 mA power loop too with my M5Core2; but I do not.
When I set input mode I see about 82 mA drawn from the battery. When I set output mode I see about 99 mA drawn from the battery. (Note: an LED is connected to the Grove port.)
In case your still interested in my UIFlow2 test program. It's in UIFlow2 Project Zone called: M5Core2_Input_Output_Test_UIFlow2.4.6
Thanks
Felix