Embed iframe in items results in error message

I am encountering an issue with embedding iframe code in items. When I try to save the iframe code, a Word Fence error message appears. All seems fine until I attempt to save the item. I entered the embed code in the Relation field as was suggested in a video on Embedding Media in Omeka https://youtu.be/83CbskOLNO8?si=EgGyBiC6V1NEk9xm. I tried other fields as well. There is no problem when saving the code in a page in an exhibit.

Is this a known issue?

I see that I posted about this same issue in 2023. I followed directions provided in response to my last post but no luck. I am wondering if the issue with embedding iframe code is unique to items (vs. pages in exhibits).

@Iris , is your site hosted on omeka.net?

I can add iframe embed codes in my instance (v3.1.2):

image

However, I first had to add iframe to the Allowed HTML Elements and iframe.src to the Allowed HTML Attributes: