Bug: Editor activity does not accurately attribute changes to correct user

**Summary**

If multiple users are collaborating on a document at the same time, the activity records the changes as if they were made by only one user.

**Steps to reproduce:**

1. Open a document
2. User A makes an edit
3. User B makes an edit within a few seconds

**Actual Result**

Both changes are attributed to User B in the activity section

**Expected Result**

Each change should be attributed to the user who made it