I just did two merges of recordings that I personally own on multiple releases:
I noticed when entering the merges that some of them had an ISRC, so I figured I’d check those out for good measure. In both cases, when I searched for the ISRCs, no results were found. However, I could locate the recordings by artist and title, and they came up with different ISRCs.
Is this something I should be concerned about? Should I remove the ISRCs I couldn’t find? Here are the edits where the ISRCs were added: