On iOS and iPadOS, I often hit the button at the top left expecting to go back to my previous note rather than the list of notes. I think a different symbol, like one depicting a list, would make more sense for this button.
Furthermore, the look of the real back/forward buttons when history navigation is enabled doesn’t really fit the rest of the controls and takes up vertical space unnecessarily.
The ideal for me would be to have back and forward buttons on the same line as the confusingly-back-to-list-view button (with a different icon), perhaps like this discount mockup: