This issues shows for me from time to time but it seems to show mostly with available deployments and on the old Software Center. If there is only one title in the 'Installed Software' tab you generally can't select the uninstall option as it is grayed out. This seems to commonly happen when i switch to that tab but if there is multiple applications I am able to click on a different one and return to the newly installed one and 'uninstall' becomes available and when there is only one on that tab you can't 'refresh' the code to validate 'uninstall'

Also when you have an application that is already installed and the deployment does not 'install' but the detection method determines it to be already valid the uninstall option generally is not available in this situation.

I see no reason for the uninstall to even NOT be an option so my suggestion is to remove whatever code is validating the availability of the uninstall button