disconnect AW ultra from iphone?

I’ve been using my Apple Watch ultra and I’ve been loving it for a few months. I love going for runs without my phone on me. I only have one dread; when I need to go for a run without my phone, I can’t disconnect my iPhone from my watch and use the LTE I’m paying for unless I turn off my phone or I go far enough away from the phone. When I play music on my watch, the music gets choppy cuz it’s losing phone connection. Any idea of how to disconnect the phone without shutting it off?