Can't automount smartphone in LXDE anymore

I used to plug in my smartphone into my laptop to access the internal storage as well as SD-card storage. Since some recent updates it stopped working. I unfortuntaly cannot narrow it down to a specific date or update, because I didn't mount it for some time. Mounting the smartphone was a two-step process in LXDE, because after plugging the phone, I had to change the phone's behavior (lineageOS) from pure charge mode into file transfer mode. After plugging the USB cord the drives appeared along with the message whether I wanted to mount it. After switching the phone to file transfer mode, the directories and files started to appear inside LXDE's filemanager. Now, after plugging the phone, I directly get a message about .service file. I can acknowledge that but the drive's folder stays empty even after I prompt the phone to switch to data transfer. I can exclude the possibility that some updates on the phone might have triggered that, because I ommitted some oft those for a while (different story). The error message is: The name : was not provided by any .service files n.m is different after reboot. I figured out, that this message is somehow d-bus related, but nothing further. I do not know how to debug this behavior or where the real error messages from d-bus might be stored. What logfile do I have to search for? Why could updating of e.g. - dbus - lxde or anything have affected the correct mounting process for my phone?