Likely meant paid an LN Invoice using Cash App (USD) balance. I think even paying on-chain using Cash App (USD) balance is permitted.

But I've had LN invoices that I've tried to pay, using Cash App, that remained pending for a while -- from several minutes up to several hours before showing completed. And one trx where the transaction was pending until it got canceled some time later, like 24 hours or something like that. I"ve been using Cash App for years, and these are rare exceptions, definitely not the norm.

But they do happen. Not your keys ...