Losing weight but my logs of last month told me I should of gain weight. What gives?

This may seems like a weird post but I'm worried for some reason.

I'm 6f1, now 171 pounds as of this morning and I'm 31M.

My sedentary TDEE is changing overtime with my weight but its average is 2217.75 calories.

During a normal day (only working, commuting and being at home), I do 7500 steps.

As for my extra calories:

When I walk (6.5km/h), I'm using 50cal/km of burned calories.

When I run (11km/h), I'm using 65cal/km of burned calories.

When I bike (20km/h), I'm using 25cal/km of burned calories.

This is my chart of my last month. I keep track of calories eaten and calories burned extra from normal day (extra walk, runs and bike rides. I don't count chores, shopping or anything for survival. I only count pure exercice time) : https://imgur.com/Z47S8KY

Basically, in the last 28 days, I've lost 6.2 pounds, which is great. The thing is, I've calculated every calories I've eaten during those 28 days I would say 95% of the times with a scale. I'm very rigorous about this and I'm doing it with the labels on the products and not with online sources. The other 5% I've approximated during my binged session or restaurants where I can't really know for sure so I estimate in a pessimistic way.

According to my calculations from my chart, my net calories over the past 28 days is 2445 calories or 0.7 pound GAIN. In reality, I LOST 6.2 pounds. I'm not complaining here but to me, this is very troubling because I'm literally counting everything and I also keep track of every exercise I do and I'm technically 100% sure I'm not off by 5.5 pounds of my calculations it's just impossible.

I'm running a lot it's my main course of exercise.

What's going on here? Am I losing muscle? I never been this in shape in my life I've destroyed my half-marathon last week. Everything is going great. I thought that logging everything would help me focus. It did but I thought the numbers I was gathering would be somewhat coherent with the reality I'm seeing. I can say today it's really not.

The only BIG CHANGE I did is quit diet soda. I used to drink 4-5 cans a day before this month. I drink 0 now it's all water now.

Can anyone give me some insight or views on this? Should I use a bigger sedentary TDEE? If I use the 1.35 TDEE, it add 320 calories to my current TDEE. 320*28 = 8960 or 2.5 pounds, which is still 3.7 pounds off the reality. I'm maybe overthinking it since it's working I guess but I just want to make sure that the weight I'm losing isn'T too much muscles or maybe my burned calories is too low and I should calculate more than what I'm using now.

Thanks in advance everyone.