Broken: every Version that I tested
Short description of error
When you cycle through combo box entries via Ctrl + mouse wheel and the entry was previously showing only a name (like "None") without an icon and you switch to an entry that has an icon prepended (like <Coloricon> Color) this icon is only shown when you expand the list and click on it.
Exact steps for others to reproduce the error
Load the file, cycle through the Initial Color on the Dynamic Paint Initial Color Panel via Ctrl+MW or via left click. Notice how the initial state (with / wo icon) defines, if an icon appears or not.