Using vital wheat gluten instead of flour

In theory chakki is a flour mill, and chakki atta is flour fresh from that mill. Realistically of course nothing you find on your grocery store shelves is fresh from a mill.

Atta flour is made from hard wheat, which has a high gluten content. This means that your flour is probably better for bread than typical all-purpose whole wheat flour from the baking aisle. If it is hard white wheat this might explain the color, as ground white wheat doesn't look that much darker than all-purpose flour.

Like typical grocery store whole wheat flour, atta flour is coarsely ground. This may give your bread a more grainy texture (not a bad thing), and makes atta unideal for cakes, biscuits, and quick breads unless you like them with a coarse texture in the crumb. If you would like to use whole wheat for baking other than bread, whole wheat pastry flour is the usual suggestion (or grind wheat yourself to a very find grind).

The rubbery texture can be from over-kneading when combining the burgers. For some recipes, I have pre-baked at a low temperature then grilled to get the right texture on the outside. This would work with a recipe with a resting period as well as one that just dries.

Also, if the egg replacer is not binding correctly (I am assuming you are using Ener-G), try using a chia or flax egg (1 tbsp of either milled, then combined with 3 tbsp water and set to congeal). This will raise the moisture in your patty, which likely already has a good amount based on your recipe, so you can use other wet ingredients instead of adding water.