python request getting different result than postman

I am attempting to improve my python by working on a side-project, just interacting with websites to look at avaialble golf tee times. Zero intention/plans to do anything commercial, this is just a semi-practical way to learn more about the requests library and web site/api interaction.

If I use the same URL, headers, and JSON payload, I get back two different results. In both cases I get status 200, but using postman, the result body is json data of available tee times for a given date and golf course.

If I post the same request using python, I get back html/website data and not the JSON. I've attempted as much debugging as I can, like verifying the headers and body are set the same for both requests. Also no authorization is being used in either postman or python. What else can I check or how can I test this further?

Im including code of the API/website request, as well as screenshots from Postman.

for course, id in golfback_courses.items():
  gc_url = "https://api.golfback.com/api/v1/courses/" + id + "/date/" + golf_date + "/teetimes?utm_source=drumm_farm_website&utm_medium=button&utm_campaign=tee_times"
  headers = {"Content-Type": "application/json; charset=utf-8"}
  payload = json.dumps({'sessionId': None})
  print(f"Tee Times for {course} on {golf_date}: ")
  response = requests.post(gc_url, headers=headers, json=payload, allow_redirects=True)
  
  #debugging prints and checking status codes
  print(response.status_code)
  print(dump.dump_all(response).decode("utf-8"))
  html_content = response.content
  print(type(html_content))
  
  soup = BeautifulSoup(html_content, "html.parser")
  #additional json/text manipulation and print logic once I verify I have json object

I'm also attaching a screenshot of the request and body response from postman. Im showing the headers, which for the exception of the Postman-Token, I verified all are the same on the python side, or, disabled them in postman and verified I still get the same response. The body is simply raw JSON passing in a null sessionId, i.e. {"sessionId": null}. I verified via json.dumps that the {'sessionId': None} in python encodes to sessionId: null.

Any further troubleshooting help is appreciated.