Extension Manager install/download error (not finding extension id)

Hi Slicers,

I have updated the Slicer Extension Index to contain the support for 5.6 extension version.
My extension is: https://slicer.cdash.org/builds/3603576 (for Linux build)

I checked that the CDash report have built correctly all version (Win, Mac and Linux), showing the packing symbol on it and referencing to the correct git commit hash.

However, I have tested installing it on Slicer (user installation, 5.6.2 r32448 / f10cd8c), just to be sure everything is ok. The Extension Index shows my extension in the list, by searching Diffusion Complexity, but when I click to install it an error pops up on the screen:

Download of extension failed, could not find an extension with id = 6745a15376aed8e33340f5c6

What happens here? I do not know what went wrong hereā€¦
Is this the correct way to inform a extension to be available to a Slicer stable version?
I found confusing that is citing in the CDash build information that Slicer is at Type: Extensions-5.6-Nightly.