New Apple watch Ultra 2 screen dimming at night to much unuseable.

Hi I bought a new Apple Watch ultra 2 last night and was very happy with it, at first didn't go to bed until late as I was setting it up. When I turned the bedroom lights off about 11 pm as it was about time to go to sleep I thought I would check at my blood glucose as I am a diabetic and have my current blood glucose as a complication via an app shuggah that continuously monitors my blood sugars I noticed that the screen was unreadable as it was so dim turned the light back on and instantly the display was nice and bright again noticed that my bloods were way too low had to get up and eat otherwise I could have gone into a diabetic coma. I went into settings display and brightness and turned brightness to max, still didn't make much of a difference. Been up most of the night, reset all and tried again with the same issue. I am very impressed with the watch, but there is a major bug with the software I guess as it should get brighter in a darker place, not the opposite!! like I said I have been up most of the night trying everything to fix this to no avail and upon googling there are hundreds of people having the same issue, so I guess I will ring apple in a couple of hours time and see what they have to say if they acknowledge the issue then I will keep it as they will fix it if not then I will return it for my money back within the 14 days.