I'm also concerned about withdrawals. I made a withdrawal to my wallet address after receiving my first payment on the Whirlwind platform, but I have yet to receive my Bitcoin. I chose a time interval of 0 hours, but it is now more than 24 hours.
You should have received your Bitcoin yesterday, if the transaction wasn't broadcasted there is an issue somewhere and I suggest you send your LoG through email so we can check. A lot of withdraws went through since then and we just checked everything and it seems to be working properly, so what we assume is a lot more likely to have happened is your transaction was broadcasted but it wasn't confirmed yet. In that case you need to wait for it to be confirmed or simply spend the UTXO with a higher fee.