OK I just tried with my everyday phone, similar thing, regular Android MTP, and it doesn't work either:
Code:
calibre, version 6.25.0
ERROR: Error: Error communicating with device
C:\r\src\src\calibre\devices\mtp\windows\content_enumeration.cpp:619:Failed to create folder:[hr=0x80004005 wCode=0] Unspecified error
Traceback (most recent call last):
File "calibre\gui2\device.py", line 104, in run
File "calibre\gui2\device.py", line 636, in _upload_books
File "calibre\devices\mtp\driver.py", line 433, in upload_books
File "calibre\devices\mtp\driver.py", line 409, in ensure_parent
File "calibre\devices\mtp\windows\driver.py", line 35, in check_thread
File "calibre\devices\mtp\windows\driver.py", line 409, in create_folder
wpd.WPDError: C:\r\src\src\calibre\devices\mtp\windows\content_enumeration.cpp:619:Failed to create folder:[hr=0x80004005 wCode=0] Unspecified error