Here’s another compatible hub: Digitus USB Type-C HDMI Multiport Adapter 3-Port
Perhaps s.o. with wiki-editing rights may want to add this to Tested Accessories
Just a few gotchas:
- Just connecting the hub but no power supply causes the hub to be recognized, but no signal on HDMI
- The first thing to work was connecting a USB keyboard
-
Power:
- Connecting power into the hub using the cable and adapter shipped with the L5 did not work (red indicator briefly flashed but quickly went blank again)
- Connecting power using an old USB-A power adapter and a USB-C to USB-A cable did work.
- Once power was established, also the HDMI port came to live.
- At one point I had the phone in landscape mode, when the screen went blank. When resuming, the slide button to enter the passcode was no-where in sight (perhaps below the external screen). Pushing the power button twice brought it back in portrait mode and all was well
-
Mouse:
- First I tried to connect my bluetooth mouse (MX Anywhere 2), but it was never found by L5
- Instead I inserted another hub (USB-A 1:4) and luckily no complaint about cascaded hubs so I could connect keyboard and mouse using USB.
It seems I’m all set 
Just if s.o. might have a hint regarding the bluetooth mouse, that would be swell.
Edit1:
Something’s not right here, since I connect to that hub things go awry:
- WiFi continues to have problems, it may start working OK, after some minutes it stalls, eventually it disconnects completely.
- red indicator starts to flash at some point (slowly - i.e., charger problem)
- when I disconnected from the hub the flashing quickens to several Hertz
- only rebooting stops the red indicator.
FWIW, I tried to follow this nice tutorial, on first attempt, the problems started when installing gnome-builder (it succeeded but the red flashing started, IIRC the logs mentioned the charger running hot – though I had started with a near 100% charge). Second time I was watching the video, then Gnome Builder started to download additional stuff, then nothing again. No connectivity, flashing started …
Seems I should more closely watch the logs re charging and re WiFi. Any ideas what I should be looking for?
Edit2:
In my next session my only change was avoiding the web browser. I ran gnome builder via HDMI, with lots of downloads / installs via WiFi. => No flashing indicator, no WiFi problems.
I have also seen web browser crashes in previous sessions, so that seems to be the component to watch for trouble.