Apparently "input.settings" and "user.settings" changed after updating. To avoid this on one of my other PCs, I can afterwards replace "input.settings" with my backup file, but is the format still the same (e.g. input settings added or removed?)
PS.: it would be nice if steam stored "input.settings" in the cloud instead of "user.settings". Graphics settings differ between PCs, but input settings remain the same. When I switch, I always need to be careful in case of conflicts. These could be due to different graphics settings (no problem) or different game saves (problem).