When starting, the HTML5 client reads the desktop name (as set by vncconfig -set desktop="name") and places it into the document title and the top bar.
When using the native client, any changes to the desktop name will update the window title.
When using the HTML5 client, any changes to the desktop name will be ignored.
When bug 4751 was implemented, the name was only considered on client initialization. The HTML5 client doesn't have support for the DesktopName pseudo-encoding yet.
(In reply to comment #1)
> When bug 4751 was implemented, the name was only considered on client
> initialization. The HTML5 client doesn't have support for the DesktopName
> pseudo-encoding yet.
In the initialization phase the server sends a "name associated with the desktop" which is the only thing used at the moment.
Now implemented in upstream:
Fixed in noVNC vendor drop.
Verified in nightly build using server on rhel7 and client on fedora with Firefox 69.0.1.
Tested and verified this on a client using fedora with Firefox 69.0.1 and Chrome 77.0.3865.90 on a server running rhel7.