Hey @kandb,
Thanks for the report here. We’re looking at how to best resolve this issue, whilst maintaining backwards compatibility.
Can I ask, did you first setup this block in ACF 5.10 or was it working in ACF 5.9 and the 5.10 upgrade broke it?
As far as we can see, the ACF 5.10 changed how some support properties are rendered. In 5.9.9, the raw WordPress markup was passed to your template, but in 5.10 it becomes valid CSS, which is obviously not backwards compatible for those users who coded for the raw data.
