The best people to answer this are nostr:npub1mutnyacc9uc4t5mmxvpprwsauj5p2qxq95v4a9j0jxl8wnkfvuyque23vg

I had the same issue and to use the funds I needed to transfer it from self-custody to the fedimint .. leaving around 1,800 sats in self-custody which cannot be touched due to "possible fees" .. I think I must have misunderstood what self-custody means 🤷🏼