Frozen chicken breast macros once cooked

It's really not a huge difference if you take note of the difference in calories (the roasted entry is about 5.3 calories per gram of protein, and the baked entry is about 6.6 calories per gram of protein).

I checked the USDA database, and the figures (30.8 grams of protein and 164 calories) you have for 3.5 oz is close to the values for 100 g (which is 3.5 oz) of "Chicken, broilers or fryers, breast, meat only, cooked, roasted" 165 kcal and 31.02 g protein), per the USDA database.

There is no USDA database entry for Chicken breast, meat only, cooked roasted, but there is one for "Chicken, broiler or fryers, breast, skinless, boneless, meat only, cooked, grilled," which should be similar, as roasted and grilled are both dry-heat cooking methods. The USDA database says 100 g of grill breast meat is 151 kcal and 30.54 g protein. I suspect your the "baked" entry you found on MFP is either a user-created entry with user error, or an entry that has become corrupted (a few years back MFP ran an "update" that tried to create oz for g entries and vice versa, and it didn't always work great. I think that was the same "fix" that generated the 1,000 calorie single clove of garlic.)

Moral -- you need to check database entries. Don't rely on the green check (which only means some algorithm that MFP is applying has decided that enough users have clicked the "is this entry correct button").