Yeah this is partially an issue with the ts lib that enuts uses and the rust lib cashu-lnurl uses any mint with a trailing slash will fail in the ts lib and the rust lib will always append a trailing /. I've created a PR to fix it in the ts lib. And I've updated the rust lib so it will not append a / if one is not intentionally set by the client.
https://github.com/cashubtc/cashu-ts/pull/87#pullrequestreview-1633300612