A change between 2.9.2 and 2.10 means that the contentbylabel macro now defaults to returning data from the current space only.

This markup:

{contentbylabel:spec}

• Produces results of pages with label='spec' from all spaces in 2.9.2
• Produces results of pages with label='spec' from current space only in 2.10

To get the same results back after an upgrade to 2.10, the markup would need to be changed to:

{contentbylabel:spec|space=@all}