the more i suggest a course of action, the more wife digs in to work against it or even ignore.
Does it happen when she is actively involved in coming up with the suggested course of action?
It sounds like you are proposing something, she is agreeing, she doesn't follow through, then you get frustrated/angry.
That could be what some refer to as passive compliance. She is communicating compliance while passively resisting, probably a coping mechanism to avoid feeling controlled by someone significant in her life (in this case you).
What do you think of
Beren2016's idea to start by asking what support she needs to work on the task?
Can you give us an example of how you propose a course of action and what happens after?