Sonos Radio stations missing from Browse

I love a lot of the Sonos Radio stations I’ve listened to - but sometimes I can’t find them when I go to Sonos Radio and browse the categories. 

Two examples (in app and web app) - 
If I browse to sleep sounds, I see 3 stations:
Piano for Sleeping, Rain and White Noise. 
But I remembered using others ones - so when I search for sleep I find others - like:
Rockin’ Chair, Oceon Sounds, Forest Sounds, Rainforest, Pink Noise, Brown Noise.

When I browse to Artist Exclusives, I see 9 stations, but I remembered Bjork had one and it isn’t there. 
If I search for Bjork, I find it in the search results. 

I tried the Sonos support bot - which basically told me to use search for the missing ones. 
I find that unsatisfying though. 

I hoped that browse would always be a full set of stations where I could be introduced to new stations and see all existing stations. 

I have no idea what other stations are missing from browse. 

Has anyone compiled a list of stations or have any tips on finding the missing Sonos Stations.