Android 11 phone - auto miounted by gvfsd - presence seen by gio - but no files visible with "gio list "

I can tell the phone is mounted

$ gio mount -l
...
Volume(0): moto g(8) power
  Type: GProxyVolume (GProxyVolumeMonitorMTP)
  Mount(0): moto g(8) power -> mtp://motorola_moto_g_8__power_ABCDEFGHIJ/
    Type: GProxyShadowMount (GProxyVolumeMonitorMTP)
...
Mount(1): mtp -> mtp://motorola_moto_g_8__power_ABCDEFGHIJ/
  Type: GDaemonMount
...

$ gio info mtp://motorola_moto_g_8__power_ABCDEFGHIJ/
display name: moto g(8) power
name: motorola_moto_g_8__power_ABCDEFGHIJ
type: directory
size:  0
uri: mtp://motorola_moto_g_8__power_ABCDEFGHIJ/
local path: /run/user/1000/gvfs/mtp:host=motorola_moto_g_8__power_ZABCDEFGHIJ
unix mount: gvfsd-fuse /run/user/1000/gvfs fuse.gvfsd-fuse rw,nosuid,nodev,relatime,user_id=1000,group_id=1000
attributes:
  standard::type: 2
  standard::name: motorola_moto_g_8__power_ABCDEFGHIJ
  standard::display-name: moto g(8) power
  standard::icon: phone, phone-symbolic
  standard::content-type: inode/directory
  standard::size: 0
  standard::symbolic-icon: phone-symbolic, phone
  id::filesystem: mtp:host=motorola_moto_g_8__power_ABCDEFGHIJ
  access::can-read: TRUE
  access::can-write: FALSE
  access::can-execute: TRUE
  access::can-delete: FALSE
  access::can-trash: FALSE
  access::can-rename: FALSE
  filesystem::type: mtpfs
  filesystem::remote: FALSE

but I can't see any files

% gio list mtp:host=motorola_moto_g_8__power_ABCDEFGHIJ

shows nothing.

How can I see the files? I remember in earlier Andriod version doing something on the phone to make files visible, but I can't find any information about it know. I have developer mode on, but I don't see any further options under developer options that might be helpful.

I am asking this on askubuntu because I am not certain that should expect to be able to see the files - perhaps it is a problem with the way I am using gio?

EDIT (1)

I tried unmounting

$ gio mount -u  mtp://motorola_moto_g_8__ABCDEFGHIJ/

and using the ubuntu package android_file_transfer

$ android-file-transfer
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
upload worker started
probing device...
probing device...
probing device...
device found, opening session...
device info "motorola"   "moto g(8) power"

then a message box pops up

No MTP storage found.  Your device might be locked.
Please unlock and press retry to continue or abort to exit

It sound like a problem on the phone side - although I have no idea how to unlock it.

Eventually I found the correct developer setting ON THE PHONE as described here

Default USB Configuration/File Transer

Now the files are visible with

% gio list mtp:host=motorola_moto_g_8__power_ABCDEFGHIJ
...
...

There was no problem on the Ubuntu/gvfs/gio side.