please help advice needed

If your TDEE is 2685 and in order to lose weight your should drop your daily caloric intake by about 20%, so 2685 - (.2 x 2685) = 2685 - 537 = 2148 calories to eat per day. Now if you work out that day and burn 500 calories you can "eat back" those additional calories or 2148 + 500 = 2648 for that day. On days you do not work out you have to stick with the 2148 calories.

If your TDEE is 2685 and in order to lose weight your should drop your daily caloric intake by about 20%, so 2685 - (.2 x 2685) = 2685 - 537 = 2148 calories to eat per day. Now if you work out that day and burn 500 calories you can "eat back" those additional calories or 2148 + 500 = 2648 for that day. On days you do not work out you have to stick with the 2148 calories.

Unless you included exercise in your TDEE, in which case you don't eat them back.

If your TDEE is 2685 and in order to lose weight your should drop your daily caloric intake by about 20%, so 2685 - (.2 x 2685) = 2685 - 537 = 2148 calories to eat per day. Now if you work out that day and burn 500 calories you can "eat back" those additional calories or 2148 + 500 = 2648 for that day. On days you do not work out you have to stick with the 2148 calories.

Unless you included exercise in your TDEE, in which case you don't eat them back.

This^ Typically TDEE should include all of your activity including your workouts, and you don't eat back calories. Yes, it might be different on workout days versus non workout days.... I just eat a little less on non workout days.

Yes, but if you use the MFP calculator, it is designed such that you eat back your exercise calories. So, it depends.

Yes, I assumed when the OP figured out TDEE that they wanted to do custom goals.

Agreed - pretty sure you're right but just wanted to clarify just in case. Good information.

I really don't understand this. I'm not losing weight and I've been working out for the past month at least 4/5 days a week in the gym and burning about the same. I've also added strength training. I'm beginning to wonder if I'm eating too little.

If you let MFP set your calorie goal, you are supposed to eat back exercise calories. (some people say they don't eat them all because they think the exercise cals in the database are too inflated). MFP sets your calorie goal low, not including exercise and then when you do, you need more food for fuel.

You can figure out your own goal that includes your exercise and then just take a flat 20% off (or less if you are closer to your goal weight).