Tested with Firefox on Windows 11 against 4.18.0. When pressing ctrl+t to open up a new tab and returning to the web access tab, the ctrl key is still being pressed down. This bug has been fixed upstream: https://github.com/novnc/noVNC/pull/1881
Tested pressing ctrl+t repeatedly with speed after the noVNC vendor drop and could see that we always release the ctrl button when a new tab is opened.