about 4 years ago - Sleipnir - Direct link
Tough for me to say what could cause this. One thing you could try is deleting your player settings (where hotkeys get saved) folder.

You can find the playersettings folder at these locations depending on platform:
Location on Windows: C:\users\you\appdata\locallow\Unknown Origin Games\OddRealm
Location on Mac: ~/Library/Application Support/Unknown Origin Games/OddRealm
Location on Linux: ~/.config/unity3d/Unknown Origin Games/OddRealm

Keep in mind this resets ALL players settings. It won't delete your save files--those are the other folders.

Hope that works for ya.