Following your advice I updated both Spacedesk driver to v1.0.15 and Intel(R) HD Graphics 5500 but the problem was not solved.
Everytime i launch Spacedesk app on android client the blank screen „Connected – Display OFF“ appears.
I noticed that the Spacedesk driver on primary machine detects the incoming connection, then it disconnects. I’m uploading the screenshots if this can be useful to you.
I also relaunched the diagnostic tool and the result is attached below.
Thank you so much for any suggestions.