How is merge-request status set

How is merge-request status set

I’ve not seen any issue when using the Merge-button, but when doing git commit and push from the command line it sometimes picks it up and sets “Merged”. Other times it does not.

Our team wishes to use fast-forward MR, an another team wishes to use merge MR.

Two repos have the same MR-settings (Merge commit), but instead of using --no-ff, --ff-only was used on the command line. In one of the repos the MR-result is Merged. In the other it remains Open.

We’re using a really old Gitlab Community edition 10.3.3 888cf31.