My computer doesn't recognize my phone, neither on ubuntu nor windows
This is one of those things that can be tricky to fix I think, because there are multiple points of failure (getting 2 different hardware devices to communicate over USB through 2 further operating system layers). But as AndrewT mentioned, my guess would be the drivers.

If I remember correctly I've had several episodes before of playing musical drivers + USB cables. I'm pretty sure what ended up happening most often was I'd finally get a successful connection upon switching cables (after focusing on reinstalling drivers over &amp; over for a few hours). I also recall one time, the solution was switching from the USB 3.0 port I was using to a 2.0 port which fixed it instantly after hours of madness trying various drivers and cables.

You said you've tried a few of each of those though. One thing to keep in mind is it can be surprising just how picky your phone can be in terms of the cable you use. A couple times I've tried at least 4 or 5 different (microUSB) cables, switching back and forth and alternating with yet another driver install only for it to keep failing. Then when I eventually desperately dug a spare cable out from the couch cushion or something, it suddenly worked like a charm. I confirmed it on those occasions too by going back to each of the previous cables once I was 100% sure everything was indeed working, and sure enough, they all refused to work; only the weird, thin, chinese crap cable from who knows where seemed to do the trick. Android can be extremely picky, that's sort of the gist of what I've seen anyway.

Your "Further Info" makes me believe even more that it's probably your drivers though, if you know for sure that the connection stopped working following a driver update, and knowing that it DID work prior to that. The final thing I can offer is that I've ran a few LG phones over the years too, and I think they're particularly bad with fragmenting the driver situation with their own driver packages &amp; LG-branded "Control Center" or "USB Tool"-type apps. While the android Universal Drivers have generally worked for most of my phones most of the time, I want to say you should try looking for any &amp; all alternative drivers out there, especially if you can find some from LG's site specifically - that might be simply the only thing that will work, while all of the other usual "Universal" android software packages out there won't (for whatever reason).

But yeah... keep experimenting, try as many different connections as you can in The Trifecta (drivers, cables, USB ports), borrow some friends' cables or computers if you have to. I bet a single lucky one of them will suddenly work like nothing was ever wrong, and likely for no reason, as frustrating as it is.