test case:
1) spawn in EGLM on a runway,
2) enable battery (and apu if you want).
3) Set NAV1 to LON 113.60, DME should show around 11 miles.
4) Set ADF1 to WOD 352.0 (it's 5 miles)
5) Rotate NAV/ADF gauge to set proper nose bearing.
6) Now, if you start to toggle needles between NAV and ADF, you will see, that thin needle are showing right bearing to both LON (about 94) and WOD (about 233). But thick needle does not work at all.
FG2020.3.13, Windows.