Also working on 10.5.1 on Linux. Hmm, do you think changing this through the web adaptor rather than on the server makes any difference? I accessed the admin page through the web adaptor to make these changes.
Nothing notable. Also using Tomcat.
I do get, "The web server was found to be stopped. Restarting it" which coincides with my attempts to update properties. Maybe there is issue where it knows it has to restart Portal to apply changes, but it is reloading an old configuration as it does so for some reason?