Spend (via sigpay.sirion.io): Invoice expired but fm-sats deducted

[justinmoon]

Reported by @yojoe in fedimint repo. Moving here because it's a client-side problem.

Everytime I spend fm-sats to pay sigpay.sirion.io invoices, the fm-sats are immediately deducted from my fluttermint wallet, but never seem to reach the BTCPay Server (sigpay.sirion.io). How is that even possible? I thought the LN Gateway can only redeem the fm-sats once it received the payment hash from the target (BTCPay Server)?

[justinmoon]

Can you share what version of fluttermint you're using, and where you installed it from? You should be able to click on the "fluttermint" title and it will show you.

What's happening is that your sats are being put in an escrow for the gateway, but the gateway is failing, and fluttermint is failing to claim them back.

Fluttermint implemented refunds, which should work if the gateway fails immediately. But if the gateway times out your sats could get stuck for a few hundred blocks ... and the UI doesn't explain this very well yet. When you pay is there a long wait before redirecting to the home screen?

[justinmoon]

Just verified that this happens on the most recent testflight build. odd ...