After running the following commands:

git checkout feature
git add .
git commit -m "done"
git push

Over on GitHub, it shows that feature branch is 1 commit ahead of main, I believe the graph looks something like this:

*(main)
   
    
     - - *(feature)

I then merged the pull request from feature into main using the “rebase and merge” option.

However, after merging, the feature branch now shows:

This branch is 1 commit ahead of, 1 commit behind main

I expected the main and feature branches to be in sync at this point, with a graph like this:

*
 
  
   - - *(main,feature)

The graph actually looks like this:

Why does this discrepancy occur?