OSD Stuck in Pending downloads

hello guys ,

I am facing an issue with windows 10 reimaging .
suddenly all actions are stuck in “Download Applicable Drivers and Apply” and it takes hours with no progress .
while checking client logs I found this " ItemizedDownloadsAvailable: false (action idXX).
on the sub-action “summary tab” the required files are downloaded and showing complete , cached on server.
and on action info it is showing "waiting for downloads to be mirrored"
note : the client relay is the server itself so no relays in between .

any ideas how to resolve this issue ?

What is the download cache on the clients? What is the size of the image?

I wonder if that is the issue.