I am relieved and delighted to tell you that the HDD passed the test with the remote via Settings.
If you wonder about the troubles with my network, when the HDR would not connect via ethernet, that was true even with the HDR connected to the router by a 1m cable. During the course of the repairs, the ethernet connection became active; it is now possible to connect through homeplugs with the HDR in the next room.
Let me repeat how deeply grateful I am to all who helped me. I really value the clarity of the advice and you patience in providing it.