- https://mint.minibits.cash/Bitcoin/v1/melt/bolt11

- https://mint.minibits.cash/Bitcoin/v1/swap

{detail: "non-hexadecimal number found in fromhex() arg at position 0", code: 0}

LNbits have similar issue with old proofs, the difference is that the stuck proofs on LNbits are actually hex, but from a very old keyset.

I am using cashu-ts on the new nuts.cash (not released yet)

I can send you one of the problematic proofs via DMs if you read them.