When setting UHF Radio Frequency Mode Dial to GRD, the frequency on the radio panel is updated but the UHF Repeater on the front dash does not show the guard frequency.
How to reproduce: Create Fast Mission, A-10C, From runway, Rotate UHF Radio Frequency Mode Dial to GRD, Look at the Radio Panel (243Mhz), Look at the UHF repeater (251Mhz).