In my opinion RESET pin should not be left floating. Try to connect pull-up resistor to 3.3V in 10k-20k range. Check L01 OEM Baseboard schematic: https://docs.pycom.io/product-info-datasheets/oem/l01_reference Edit: Sorry, now I noticed the reset pull-up already being in your schematic. Anyway try to use FTP client for script uploading.

@robert-hh Thanks, I am working on a very small laptop so I didn't see that as it wasn't very obvious :-)