No error shown for the user when creating pull request and push changes to dependant branch

So:

1. I start creating pull request
2. Then pushed some changes to destination branch of my PR
3. Press create a pull request button
4. Nothing Happens ;(

The Network tab shows me and error that destination branch was changed(error: 'The branch develop (c79daaebeee6) may have changed. Refresh your page to get updated branch information.' But this error is not shown for the user.