This is a question which seems to have been asked many times - mostly between 5 and ten years ago. I still have had this intermittently (as do others I see with a variety of phones, computers and ubuntu versions) trying to connect my Nokia 3.4 to my Dell based Ubuntu 22.04. Usually a disconnect/reconnect of the cable makes it work. However, there was one period last September when I could not get it to work at all. I simply gave up for a few weeks until it suddenly started working again - Yippee! - Until this week, when it has failed again. I strongly suspect there is some update somewhere which is causing this on/off behaviour.
I've tried different USB ports and cables. Running gmtp makes no difference - it says 'No device attached' - despite my phone showing up in my file manager etc AND gmtp (wrongly) recognising it as a Nexus/Pixel as below!
I have obviously looked at many other threads and sources to try and sort this out and I see that the most often responses are for the outputs of lsusb and mtp-detect to be posted so, here are mine:
$ lsusb
Bus 001 Device 005: ID 0a5c:5800 Broadcom Corp. BCM5880 Secure Applications Processor
Bus 001 Device 004: ID 8087:07dc Intel Corp. Bluetooth wireless interface
Bus 001 Device 038: ID 18d1:4ee2 Google Inc. Nexus/Pixel Device (MTP + debug)
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 003: ID 413c:8187 Dell Computer Corp. DW375 Bluetooth Module
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
$ mtp-detect
libmtp version: 1.1.19
Listing raw device(s)
Device 0 (VID=18d1 and PID=4ee2) is a Google Inc Nexus/Pixel (MTP+ADB).
Found 1 device(s):
Google Inc: Nexus/Pixel (MTP+ADB) (18d1:4ee2) @ bus 1, dev 12
Attempting to connect device(s)
LIBMTP PANIC: Unable to find interface & endpoints of device
Unable to open raw device 0
OK.
Interesting that my device is listed as a Nexus/Pixel - which it is not!
It would be really nice to get a definitive, permanent 'fix' for this ongoing problem.
TIA
Chris