The site tries to use all your UTXOs to get around the issue. Even with mitigations in place, users only have so many UTXOs and this limit still gets hit.
Could you just automatically make more utxos? Auto-split balance into a bunch of .00001 utxos or something so that it’s way less likely you’ll run out of them.
Additional mitigations can be put in place, but they require significant dev time and don't fix the root issue.
