Name your courseroom. We'll take it from there.
A graded stage of the final project rather than an assignment in its own right. Handing the stages in separately lets an instructor comment on your direction while the later sections remain unwritten. That is the entire design: the correction reaches you at a point where acting on it is cheap, instead of once everything downstream already depends on it.
The first figure gives the module a stage belongs to and the second its position inside that module, so a 4-2 is the second graded item of module four. The scheme communicates timing and nothing whatsoever about how the stages relate to each other, which is the part that decides how the course goes.
Eight weeks. Since the stages run in sequence, a lost fortnight cannot simply be made up by working on several at once, because the fourth module's piece frequently assumes the second module's already exists. Compressed terms also hold nothing in reserve, so illness or a demanding stretch at work removes a quarter of the course.
Usually enough to settle the outcome, and its criteria are not equally weighted. Rows concerning reasoning and use of evidence commonly carry a multiple of what the rows on formatting and presentation carry, even though the grid shows them at identical size. Finding those weights before drafting is worth more than any later polishing.
Repair it ahead of whatever falls due next, which feels like the wrong order. Every later stage inherits what the earlier one established, so patching the current piece on top of a faulty foundation only relocates the problem. Comments on an early stage read best as instructions for the next submission rather than as a judgement on the last.