Your logs have been inspected. I was told it has simply to do with a lack of diversity. You seem to have too few albums of each genre, style or decade.
Have you created custom “albums”, where you collect all tracks of a certain style all in one or very few albums?
The server has a default threshold of 15 albums, below which it doesn’t allow to start a radio.
You can experiment with the hidden server preference RadioDirectoryThreshold and assign a lower value than 15 in there. But it might not be very satifying.
