Avoid banner or flash message to create merge request for specific branch

Hello everybody,

I have a branch that I do not want to merge to master under any circumstances. However, on every reload of the project overview page Gitlab displays a banner / flash message / reminder offering me to create a merge request for this branch. Usually it is good thing but I do not want this to happen in this case. Is there a way to get rid of this banner / flash message / reminder? I already marked this branch as protected but it the flash message still pops up. Do you have an idea?

Thank you very much. Best Regards