Hey there stevkazt,
The first thing we wanted to provide was the link that talks about using Continuity Camera, the requirements, and the steps to take if it's not working as expected: Continuity Camera: Use iPhone as a webcam for Mac
According to the list of 'Additional requirements' near the bottom of the link above, it does list a requirement that your iPhone must not be sharing its cellular connection, and to be connected to Wi-Fi. Since you mentioned using your iPhone Personal Hotspot, we recommend turning off Personal Hotspot, then connect both devices to a regular Wi-Fi network per the requirements.
If you still need help after making sure you're meeting all of the requirements on both devices, along with trying the steps the link provides for issues with Continuity Camera, then the next step would be to reach out to Apple Support as they'll be in the best position to assist further: Get Support
Take care!