Why are you paying $600 over Lightning tho? It's cheaper via on-chain. LN payments above 150K sats have a good chance of failing if you only have a single channel / bad channels. What channels are you using by the way?
Discussion
If $600 is a big payment for you, I understand how your future self depends on BTC NGU.
What would be helpful to know is that all payments below a certain amount e.g. $10k always go through especially when fees around $100 to secure the BTC chain will be the norm in a couple of years.