If genmon is configured to display only an image, it is impossible to show the properties dialog by right-clicking on the image. Reproduce by adding a genmon plugin to a panel and unchecking the label box. Configure the plugin to run any command that displays an image, but no text. Right-clicking on the icon, which is the only visible element of the plugin, has no effect. xfce4-genmon-plugin 3.2 - Generic Monitor
Created attachment 1588 shell script to display an image, but no text, in genmon This shell script toggles between two images and does not display any text. Configure genmon with an update period of 1 second and disable the display of a label.
Created attachment 1596 patch to attach plugin menu to wButton widget This patch enables the display of the plugin menu when a user right-clicks on the button, if it is displayed. This patch appears to fix this bug. Use previously attached shell script to test.
Patch applied. Thanks