Calibre was communicating with Android phone, now won't

[SteveG23]

Using Windows 11 Pro, Calibre 9.7. I had cleaned off the library from my Android (Samsung A54, Android 14) phone to make sure Calibre 9.7 was managing it properly. I got the library on the desktop PC and then on the phone back to a fresh start and used Calibre to load a few dozen of my existing epubs. Then I took a bit of a break and found that the last batch of files I tried to copy hadn't gone through. I tried again, and now I consistently get the dreaded "error communicating with device." In the Details, I get:

C:\r\src\src\calibre\devices\mtp\windows\content_e numeration.cpp:855:Cannot write to file:[hr=0x80004005 wCode=0 name=unknown] Unspecified error

Calibre does read the library of files already copied to the device; just won't let me add new ones.
I have tried:
> rebooting the computer and the Android device;
> deleting driveinfo.calibre and metadata.calibre
> changing to a different cable and USB port
> making sure I can read the device folder from my computer in File Explorer before restarting Calibre

What have I not tried?

[kovidgoyal]

Thats an error trying to write a file to the device, if rebooting it and computer doesnt work then your remaining options are reset the device or use one of the wireless transfer methods.