Undo should stop working at a certain point

[royk]

I created a note, edited its content & saved it. Then I changed to different views (card, article, mindmap), and then did a review of my notes.
After finishing the review I clicked the "undo" button, which then undid the first action ("edited a note's content"), even though that action was done, from a user perspective, a long time ago in a different context.

I did not expect to lose my note at this point, I believe this is bad UX.