Weird. I had no trouble with Phoenix, and 4 sats was the estimated fee but the payment went through at 1 sat. The fee estimate is just an estimate until the route is attempted, and it’s often less.

Are you on the latest version? 

 Where do I find my LNurl in Phoenix?

Or should I just use WOS and transfer over when needed? 

 Yeah, Phoenix doesn’t have that capability. You’ll still need a wallet with a Lightning address for zaps. If you’re not in the US, WoS is an option, along with Alby and LN.tips.