Good morning.  Is this v1 or v2 VSA?  If v2, is that a parent or child job?

Hi!

its V2, and it's a parent job

I also opened a case with Commvault but the answers so far are not convincing me.

"The Streams tab shows only the "Device Streams" to the Storage Policy; it does not include the "Data Readers" from the VSA subclient."

What about READERS IN USE in the image?

That is most likely where the difference is being seen, the parent job may be showing all of the streams of the child jobs as v2 jobs are multi-streamed.  Is this a Synthetic Full backup?

Support said that the "Number of Readers in Use" does not refer to data readers, but device streams.