I am unable to set ADF in several missions, for example in mission 1 - Batumi 430 kHz, in mission 2 - Kobuleti 490 kHz. I tested Kobuleti's outer beacon (870 kHz) - doesn't work either (tested in mission 2).
In mission 3 I easily picked up Kutaisi's NDB (477 kHz). I've also tested Batumi NDBs in mission 3 - with no luck.
In some missions Batumi (430 kHz) is ok.
I generally have no problem using ADF in Huey and I tested all these NDBs during my flights (missions outside of this campaign) - with no problem.