System Information
Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 430.39

Blender Version
Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: rBf6cb5f54494e
Worked: (optional)

Short description of error
defining a new keymap entry uses a different locale than the actual system keyboard

Exact steps for others to reproduce the error
I use the german keyboard locale (so some keys are swapped relative to american/english)

Try to define a new key mapping under preferences/keymap:
click on a key definition so that "press a key" appears.
when I hit the key which shows (on the german keyboard) "#"(hashtag), I get "/"(slash) entered instead.
if I store this and go back into the edit view, hitting "#" does not work.

if I do this with a key which has the same position on the german and english keyboard (e.g. "." or "a") it works
(of course I have to delete the other definitions for the selected key beforehand)