JS Error when unticking "Show arrow" in views: Expected double-quoted property name in JSON

The issue is caused by a malformed JSON if the arrow option is left out:

Actually the same problems happens with "Show dots"...

GitLab is playing funny today. And I made a mess:

1. MR!26 - 3378680-json-malformed: this is the good one
2. MR!25 - arrow-json-malformed: Initial draft but GitLab doesn't let me close it
3. branch 3378680-js-error-when: automatically created but it is not appearing in my fork

Please review.

Thanks

Well the pipeline is failing, no idea why but I can't merge.

On GitLab it says "Missing CI config file. "