When leaving a CTR and flying into the TMA, the "Radio" button doesn't always list frequencies.
One example - Flying a direct route from Oslo Gardermoen (ENGM) to Kjevik Kristiansand (ENCN). The behaviour below is also seen in Simulate mode.

- In ENGM CTR "Radio" lists the CTR and TWR frequencies correctly.
- Leaving ENGM CTR the plane enters Oslo TMA. Location is north-east of the capital Oslo. "Radio" lists different frequencies correctly.
- However, as soon as the plane passes Oslo downtown and location is south-west of Oslo - still in the same Oslo TMA! - "Radio" popup wndow is empty.
- Continuing, the plane leaves Oslo TMA and enters Farris TMA. "Radio" is still empty.
- Approaching Kjevik TMA, "Radio" only lists one local frequency (Gullknapp Radio, ENGK). No TMA frequencies.
- The plane has to enter the Kjevik CTR before "Radio" popup lists any frequencies.

The "Radio" feature is great when working (which means with CTR). But it is useless when in TMA. When outside TMA on the above route, "Radio" should list Norway Control frequency. So it means I can't rely on "Radio" to always give me a frequency when needed.

I tried the same thing flying out from Vaernes TRodnheim (ENVA). Same thing.

I am also missing the TMA frequency when tapping&hold within a TMA in Norway.

I created a route from Oslo Gardermoen (ENGM) to an air field in Sweden. There "Radio" lists "Sweden Control", "Information" and TMA frequencies along the whole route.
Tap&hold also shows TMA frequencies (when within a TMA area).

So why is this not working properly in Norway airspace?