we've been talking about reducing variables, right? ;-)
So, remove those batteries & use a PSU. Remove USB also (data wires might be a little long anyways) & solder reset to gnd to bootup priiloader.
Then shorten the wires of the regulator, as short as possible.
After that, turn it on & measure the voltages on the board.
(Also did you check for shorts between each of the different voltage lines [and gnd ofc]?)
And did you recheck the U10 after trimming?