Maybe do the same calculation for the past four weeks? It's called a period because it's periodic, of course, so getting one cycle should negate that (as four weeks ago you were presumably retaining water too). Or, go from six weeks ago to two weeks ago to be clear of that effect but still at one cycle?
On 7/18, you were 188.1 lbs (congrats). One 6/20, you were 193.9 lbs. So, that's a delta of -5.8 lbs (congrats
). That's 1lb/month more than your past two weeks (-2.4 lbs/2 weeks). Adjusting your calculations accordingly, your BMR would be 1325 cal and your TDEE would be 1943 cal.
You could be missing added butter, oils, and other condiments in your log, or could be underestimating portion sizes. Or, you could be running a bit more efficiently (i.e. slower metabolism). And, of course, your FitBit could be optimistic. Maybe check to see that it has your current weight. And, if you can't find anything from any of that, just adjust the data by your weight loss and go with it, as you have been.
Nutritionally, I'd consider replacing sugary drinks with low calorie versions and using those formerly wasted calories on stuff more protein-rich. You'll be more satiated and have the building blocks you need while on a caloric deficit.