Lockscreen: logging back in disables dock keyboard and mouse
I'm using a brand-new Dell Precision 5530, with Gnome 3.28.2 installed. I plug my laptop into a Dell Thunderbolt dock, and the dock provides power, ethernet, and keyboard and mouse (both plugged in to the dock via USB). When I lock my laptop (either through inactivity or through Super+L), and unlock it later, power and ethernet still work, but keyboard and mouse are no longer responsive. I can only regain keyboard and mouse by unplugging from the dock, and plugging back in again, but even then, it's erratic whether it succeeds or not. I've checked Settings > Devices > Thunderbolt, and it claims the thunderbolt dock and thunderbolt cable are both recognized and authorized, so I don't know what setting I ought to check to try to regain my keyboard/mouse.
Apologies if this is a known issue or fixed in newer versions of Gnome Shell; I can try to update if that's the case.