Apple Watch sleep tracking without enabling Do not Disturb??

Hi! I wanted to know if anyone knew how to be able to use the sleep tracking function on the Apple Watch without enabling do not disturb on the iPhone. I haven’t been able to find any setting to allow for it. I don’t have a regular sleep schedule and don’t like to use do not disturb to not miss important messages or WhatsApp notifications as has happened in the past. Please let me know if anyone has been able to crack this! I have the sleep tracking setting enabled but whenever I turn off do not disturb it doesn’t track! I haven’t been able to get a single night’s reading.