So, I have an LG L5 II that works regularly, except for a few hiccups that don't bother me too much; I had the L4 II and already knew "the flaws" of this series.
Getting to the point, sometimes it happens that the data connection (practically the one strictly linked to the SIM and not the Wi-Fi one) starts on its own; this morning, for example, this happened: I turned on the phone (which I had turned off last night, which I don't usually do) and a strange situation presented itself; it was as if it had been re-initialized but without deleting any internal data, not even on the SD card (everything remained intact), and besides this, the two programs I installed for "security," an antivirus and an anti-malware, would not start; basically, they gave an error. So, while for the anti-malware the issue was resolved almost immediately by managing to get it running again, for the antivirus (which I think I had set as system administrator, meaning in case of theft or other problems the software in question would have deleted all data returning the phone to its base state, as if it had just come out of the factory, except even if this had happened, no data was deleted), after a few minutes, while trying to reinstall this antivirus without the procedure starting, the dialog window for its startup opened and I was asked for the password I had entered at the time of registration; after this step, the software started normally and scanned the phone.
It should be noted that no suspicious files were found, and only in recent days some redirection pages (as sometimes happens) were promptly blocked by this antivirus.
The thing in itself is not "serious," but since I also use the phone to record what I do (musically speaking), it would make me quite angry if a problem with it caused works to which I dedicate much energy, time, and dedication to go to waste.
I use the phone because it remains much more convenient: in practice, I connect the phone to the PC (disabling the internet connection on the phone; I have no active connection on the PC), transfer files from PC to phone, and then I reconnect and record; it only takes a few seconds.