Has future update of remote assistant v18.104.22.168 changed?
Interestingly there is a workaround for this problem. I did this several times and it worked, at least for me, no guarantee, whatsoever! ;-)
There is no client update option in the menu but you can update the remote client manually as a normal installation while beeing connected! I thought that I will lose all connection somewhere in the middle of the installation process but it did not! I started the installation by clicking on the file and it asks if I will close the application as it is currently running. Yes, and the connection is gone. Don't worry, simply reconnect and you can proceed the same way as if it is done on your own machine. As I remember you will have to reconnect twice. Don't panic, the last reconnect will, if done too fast, first show that the host is not running or has a different ID but a few moments later it will reconnect and show the updated version number.
I was surprised that it runs so smoothly. It would be better to have the option again in the menu but in the meantime it is ok for me. Maybe one caveat to consider: The user running the update on my remote machine has admin rights so the system is not asking for an admin password to gain necessary rights. Maybe this could be different if this user doesn't have sufficient rights in the beginning. I have not tried this case. So don't blame me if your installation is stalled when trying to gain elevated rights and it get's no confirmation.