Seriously, I have no idea how this is possible. What other apps are you using? Try disabling everything but Sidekick to rule out possible conflicts. If the issue persists, try deleting Sidekick folder (back it up first if you care about records and odometers) and installing a fresh one, doing a Steam integrity check, and/or ultimately making a fresh Assetto Corsa documents folder.
Thanks for the suggestions. I've already tried disabling all other apps. I'll backup my docs folder and see if a new one fixes it.