In season 3 Episode 6 of The Tudors, Henry starts to search for a new queen, and Cromwell’s position really starts to slide.
Here are some related episodes and links:
Alison Weir on Anne of Cleves: https://www.englandcast.com/2019/05/episode-121-alison-weir-on-anne-of-cleves/
Tudor Times on Margaret Pole:
https://www.englandcast.com/2017/07/episode-081-tudor-times-margaret-pole/
David Crowther on Thomas Cromwell:
https://www.englandcast.com/davidcrowther/