Thank you for the marc2bibframe2 converter - it's a great tool.
It looks like it has a problem with URIs in field 1xx, 7xx subfield $4, though.
The first 3 characters of HTTP URIs are interpreted as the relator code "htt" and not as a URI.
GitHub ticket: https://github.com/lcnetdev/marc2bibframe2/issues/79
National Library of Latvia