In ArcGIS Pro I created a class relationship between a point layer and a table that contains hyperlinks to other resources.
Also in ArcGIS Pro, I configured the popup with an Arcade expression so it properly displays, with HTML line breaks built into the table. Here is the popup in Pro:

Uploading this to AGOL, the popup doesn't work -- it just shows the html garbage. The case where it actually does work is when there is a plaintext url (no html from the table itself) and there is 1 record. The link text defaults to "View."
BUT when the related table has more than 1 record for a particular location, the multiple records' plaintext urls are concatenated, which of course screws up the link and defeats the whole purpose of relating a table.
This thread makes me wonder if there is no solution for this in MapViewer:
https://community.esri.com/t5/arcgis-web-appbuilder-questions/trying-to-create-hyperlinks-in-popup-from-records/m-p/1264732#M22898
Is this all more flexibly configurable in Experience?