No color highlight when searching from XFCE's Whisker menu

[cfnnmcg]

Problem:

When using the Matcha GTK theme in XFCE, if you search from the Whisker menu (Open menu -> type name of program) there's no color highlight in the list of possible matches, so it's not clear what item is selected. Even when using the arrow keys to select another item it doesn't show a color highlight, only a dotted border.

Expected behavior: There should be a colored highlight around the search results in the Whisker menu.

Happens with another theme variants? Yes, the bug happens with every theme variant (normal, light, dark) and with any color (Aliz, Azul, Sea or Pueril).

Examples:

Using Matcha Light Aliz: There's no color highlight in the list of possible matches

Using Arc Lighter: There's a color highlight around the first result

Matcha Ligth Aliz: It shows only a dotted border when selecting another item using the arrow keys

Arc Lighter: There's a color highlight when selecting another result using the arrow keys

Additional info

OS: Endeavour OS
XFCE version: 4.18
Theme version: 2023.04.03-1
Theme installed from: Arch User Repository