Unfortunately, we couldn't reproduce the issue. Could you please clarify if the issue occurs when you're using the Text Chat mode or its simplified version the Mini-chat which can be opened alongside the Full Control and View mode window?
In addition, we highly recommend that you update Viewer to the same version 18.104.22.168 that is used on the remote Host machine, as the version mismatch might be causing the issue as well. Version 22.214.171.124 is available for the download on this page. Alternatively, you can also update the Viewer using the Check for updates button located on the Viewer's ribbon toolbar, on the Help tab which will prompt to the Automatic update.
Let me know if updating the Viewer did not help and the issue still persists.