This is possibly due to the way validation is done on these actions as it is done on submit rather than on change, but this is just a hunch. If this is the case then it may be a fiddly issue to resolve.
Hmm actually I can't recreate this again now (even though there is video proof in the issue of it not working). Whoever picks this up, check it is actually broken on master first.
Steps to reproduce
Expected behaviour
Actual behaviour
Note the intended behaviour at the end of the video when switching away from Simple payment: https://github.com/user-attachments/assets/ca7d5db3-3ef8-48bf-9e46-24eaa51e5e74
Suggestions (optional)
This is possibly due to the way validation is done on these actions as it is done on submit rather than on change, but this is just a hunch. If this is the case then it may be a fiddly issue to resolve.