Undo functionality is way too aggressive

Summary

Undo functionality removes more content than expected

Steps to Reproduce

1. Type a sentence into the Confluence editor
2. Click on the 'undo' button OR type CTRL + Z / CMD + Z

Expected Results

Last word of that sentence is removed

Actual Results

The whole sentence is removed

Notes

If you type a whole paragraph in Confluence without any new lines, this is also removed by undo. Most other editors remove only the last word or action, not the whole sentence.