_wrapper_format=drupal_ajax is always added, instead of updated when the param is already available

This Patch did the trick for me, but probably room for improvement.

9.4 isn’t taking ordinary bug reports.

Changing to 11.x as it will have to be committed there first anyway.

As a bug will need a test case showing the problem.

Going to check if this issue is still present on D10. Currently upgrading a project that is using this patch

Updated patch to work with D10.2.4

Patch in #8 also worked against a 10.4.7 site.

We had the issue with a brand new installation of Webform.

The error only seems to appear on the second time you try to add/delete an element without refreshing the page:

• Select '+ Add element' at top of page
• Choose an element and save
• Select '+ Add element' for a second time (or select 'Save + Add element' in fly out menu)
• Choose and element and try to save
• Result: Ajax error in console

Same also applies for deleting. The first time you can delete the element without issue. If you try and delete a second item, the error appears
If you refresh the page in between adding / deleting the element, then the addition / deletion is successful.

Applying this patch has resolved the Ajax error. We still have a console error, but the one that was preventing new elements from being added seems to have been fixed.

Leaving as "Needs work" as it sounds like this still needs to be re-rolled against Drupal 11 though.