There seems to be a problem with the stated behaviour when one changes the options for squashing commits.
The configuration page indicates : “Changes made are also applied to existing merge requests.”
I changed the option on a project from “Allow” to “Encourage”.
Expected behaviour (according to the documentation) : all existing merge requests in the project would now have their checkboxes selected.
Actual behaviour: No visible change on a sample existing merge request, the checkbox remains unselected.
N.B. The same behaviour was noted on two different projects.
Remark : a newly-created merge request did have the checkbox selected by default (as soon as it was created).
Thanks in advance for any guidance on this point.