[field troubleshooting]: Astra DB collections pin the vector dimension at creation time, so switching embedding models (for example 1024-dim to 768-dim) breaks the collection. The fix is to delete the collection in the Astra DB Data Explorer and re-create it with the correct dimension, then re-seed. Watch for $vector value can't be empty and SHRED_BAD_VECTOR_SIZE as the signature errors. Also verify the app token starts with AstraCS, the DB is Active, and the token has Database Administrator role when you hit auth failures at the same time.

Context: Inserts or vector searches fail with a vector dimension error. The collection was created with a different vector dimension than the embedding model now produces.