Explanation :
Monstercat swapped to a new API in late 2019, API v2, which superseeded API v1 we were using.
They stopped the support for v1 in early 2020, new tracks aren't appearing anymore.
Solution :
The new API uses different IDs, and different endpoints, which will need a full refactoring of the API code. This will take a while.
Fix : Use Connect API v2.
Explanation : Monstercat swapped to a new API in late 2019, API v2, which superseeded API v1 we were using. They stopped the support for v1 in early 2020, new tracks aren't appearing anymore.
Solution : The new API uses different IDs, and different endpoints, which will need a full refactoring of the API code. This will take a while.