This error is expected when writing through a foreign catalog (Lakehouse Federation): foreign tables are read‑only, and Unity Catalog will only vend READ credentials for them, which surfaces as “Only READ credentials can be retrieved for foreign tables.”
On DBR 16.4 your interactive cluster is enforcing that policy; the older job on DBR 16.2 likely avoids the check (for example by writing to a non‑authorized path or via legacy/non‑UC credentials), so it appears to succeed.

To test interactively, either write to a managed UC or non‑foreign external schema (recommended), or materialize from the foreign table into UC using a materialized view and operate on the copy; if you must write to the same storage path that’s covered by a foreign catalog, remove the path from the foreign catalog’s authorized paths or enable the external location’s “fallback mode” to allow instance‑profile writes (with care, since it bypasses UC write governance).