Thank you Polina for the fix. I downloaded the portable viewer and replaced my existing portable viewer, and it worked. I did not update the server versions, just the viewer, and the enter and shift keys work properly.
DO you have a fix for this yet? I am unable to uninstall one drive. (nor is that a viable solution). Martin has given you a way to reproduce this issue. When do you think a permanent solution will be available?
I can confirm that this happened to me too, exactly like this, and just today. Just before doing windows updates, it worked, and as soon as I did windows updates on the host machine, it no longer worked. The KB4522742 already existed on the remote machine since Nov 20.
On the remote machine, CTRL, Shift, Enter do not work. (Thus, cannot CTRL-C / CTRL-V, cannot shift-arrow keys for highlighting, and Enter doesn't work, both of them - on the main keyboard, and the enter key in the num pad).
I am attaching a screenshot of the Windows Updates. The updates that were installed were these two: TWO Microsoft Office "Click-to-Run Update Support". "October 24, 2019-KB4522742 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10, version 1909 and Windows Server, version 1909".
I hope that helps to figure out the issue.
EDIT: I am using the latest Remote Utilities on both machines 126.96.36.199.