When trying to upload files to my Samsung S20 the GNOME file manager fails to
see any files or folders, because cdc_acm gets loaded into the kernel, which
creates ttyACM0 and therefore access to the smartphone is blocked.

rmmod cdc_acm and switching connection modes back and forth on the S20 allows
accessing the smartphone through the file manager.

Snippet from dmesg:

[42176.794325] usb 3-2: new high-speed USB device number 13 using xhci_hcd
[42176.952259] usb 3-2: New USB device found, idVendor=04e8, idProduct=6865,
bcdDevice= c.00
[42176.952265] usb 3-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[42176.952267] usb 3-2: Product: SAMSUNG_Android
[42176.952268] usb 3-2: Manufacturer: SAMSUNG
[42176.952269] usb 3-2: SerialNumber: R3CNB0272ZP
[42201.218000] usb 3-2: USB disconnect, device number 13
[42201.698482] usb 3-2: new high-speed USB device number 14 using xhci_hcd
[42201.856728] usb 3-2: New USB device found, idVendor=04e8, idProduct=6860,
bcdDevice= c.00
[42201.856735] usb 3-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[42201.856736] usb 3-2: Product: SAMSUNG_Android
[42201.856738] usb 3-2: Manufacturer: SAMSUNG
[42201.856739] usb 3-2: SerialNumber: R3CNB0272ZP
[42201.887908] cdc_acm 3-2:1.1: ttyACM0: USB ACM device