Placeholders

I have a few hundred fields. All have Click Here to Add Content as the placeholder for the field.
But some fields, even though they may be identical to many other fields(except the name), do not show the CB Core Fields Ajax Placeholder.

Any idea why this might happen?

CB Core Fields Ajax should only display the place holder for fields that do not have a value and can be ajax edited by the viewing user. Some fields always have a value like integer fields are always at least 0 except for new users where it might be NULL. You'd need to provide what field types specifically aren't displaying the placeholder.

They're editor fields. Editor fields often are never empty after their first edit. They usually end up with an empty paragraph element in them as that's the default wrapper element for new lines in the editors settings. Try editing the field and using the view source button and you should see that it's not truly empty.

I had already thought of the source code and I have checked the database.
Both were empty.

I found the solution.
If the field is set to show 'Yes, 1 Line with Title' - it does not show the Placeholder.
If the field is set to show 'Yes,1 Line without Title' - it shows the Placeholder.

Got a fix for this? Or do I need to change all my fields?

The display mode has no relevance to it displaying placeholder or not. There's no checks for that within the code. All it checks for is the following.

Is the field NULL
Is the field EMPTY STRING
Is the field Equal To "Empty Field Text" in CB > Configuration > User Profile

If any of those pass it will render the placeholder. Have also checked toggling the display mode and am not seeing such an issue.

It's possible it's just a bug in the ajax edit template. What template do you have selected in that field for its core fields ajax parameters? If set to "Same as Global" what template is selected within CB Core Fields Ajax > Parameters? If using a custom template please switch to the default template and see if issue persists.