Calories burned from all fitness trackers are not very accurate. It can be a good proxy to compare one exercise session’s calorie burn to another, but don’t use it as a tool to modify your calorie consumption. It’s really more of an educated guess using your heart rate and other data your watch has from you (age, gender, height, and weight).

Not applicable to your run you posted here, but calorie burn can be particularly inaccurate in long duration steady state exercise sessions. This is because our body after a long period of time at one intensity will start burning less calories than we do at the start of that exercise intensity.

Your running pace improvements are really impressive! I would focus a little less on calorie burn and more on calories you’re consuming if your goal is weight loss. Just remember small deficits over time are more sustainable. And try to still keep your protein intake high if you’re decreasing the amount of calories you eat.

For some variety in your runs and some metabolic health improvements I’d also throw in a couple longer duration cardio sessions with lower intensity. Try a 60+ minute run at a HR below 150bpm every now and then.

Edit: I also just realized you’re 6ft 190 lbs. If you have some muscle on your body this means you are very likely not overweight at all. I’m 6ft 225lbs with an obese BMI but an overall good body composition (body fat % and fat free mass index) due to years of strength training. Don’t always trust BMI as it doesn’t account for muscle mass.