Already merged commits in new Merge request

Situation is as following
Earlier today changes were pushed directly to master (critical issue).
Then we merged master back to develop branch. Code is now exact same on develop and master.

Then a dev checked out master and did a pull. Then created new branch for a new feature.
Few changes made in the new branch and only 1 commit.

Then we did a PR from new branch to develop branch.

Problem:
It contains many commits with whole bunch of code that is already in develop branch and has nothing to do with the newly created branch.

It is super annoying for code review.
How can we solve this problem?

(using the gitlab.com cloud version)