I've installed the client on a number of Debian platforms, including even Ubuntu, and seen this happen on all of them.
Once Horizon Client has launched a remote session, the operating system's key repeating function (when you hold a key like space or backspace down and after a second it starts repeating) becomes inoperative. Once this happens, it also stays this way until the X session is restarted or system re-booted (including after Horizon is shut down).
Was this intentional or how does one fix this or stop it from happening?
I have a similar issue on Horizon Client for Linux v 2106. Key starts repeating unexpectedly and it doesn't stop until I press a different key. (it can go like that for minutes or hours). Having ticket opened with VMware which are investigating this. Will post here the solution once I have it. Or if someone else has a solution already, it would be helpful.