That is in Vivaldi Browser on Win10 with no other scripts running on that page. Toggle your script off and the page shows ISRCs again.
I assume it is because the server hamsters have fixed this old bug:
Last week that would have been a long line of ISRCs on one line making the formatting go mad. Line feeds have now come back.
Updated: Looks like this will be the change: [MBS-12334] Collapse ISRCs and ISWCs when there are too many - MetaBrainz JIRA