When trying to alter the Input Actions via Project Settings | Input System Package | Input Actions, I am missing the Save As and Auto-Save buttons, so I can’t save my changes.
Tried it with Unity 6.0 and Unity 6.3, so it looks like it is a Input System 1.18.0 issue.
I dont remember a save as.. but

If auto-save is selected they tend to go grey’d out.
As I mentioned, the buttons aren’t there.
They’ve never been there for the project wide settings I’m pretty sure.
They show up when editing a standalone input actions asset.
It will still be saved when you CTRL-S so no need to worry.
Editin the global does in fact NOT save. I havent foudn a clear repo why it happens yet. @antenomspa you can “fix” it for now by:
clicking on the InputSystem_Actions asset in the global settings again.
This will open a sbut menu for actionsEditor:
in this one you will now see the save asset / auto save. And editing it
should save the changes
No need for the thumbs down. It should save when editing it but I guess the editor has a bug in that it doesn’t dirty the asset on any change.
Mind you the project wide input actions makes for terrible code architecture and I suggest not using it.
Thanks for raising the issue, a ticket has been submitted earlier this month. Feel free to upvote.
Regarding the missing Save As or Auto-Save buttons in Project Settings → Input Actions: they are not actually missing. They were intentionally omitted to follow the Project Settings convention of saving changes automatically.
Still don’t have any save buttons in v1.19.0, 6000.3.9f1 and none of my changes are auto saving.
For anyone else as a work around I hit a breakpoint in jetbrains rider and entered the following command to turn on auto saving.
InputEditorUserSettings.autoSaveInputActionAssets = true
For the Unity team i inspected the autoSaveToggle toggle when the GUI is being created and the width/height of the auto savetoggle are NaN.
I think we established there is if you edit it one way, and the team have said you dont need it if you edit it the other.. So if you edit the SO version in your folder structure you will get buttons, aka
if you edit it through the project settings you do not and this is by design.. aka