Reassigning Worksheets without clearing previous answers

[Melslp13]

I'm completely new to Canvas and using it for a homeschool biology course I am teaching.  My first assignment was a WebQuest with a worksheet that students had to fill out.  When work was submitted, if the student got <70% accurate, I annotated their attempt by highlighting the parts they got wrong, sometimes leaving additional prompts to help them find the correct answer. Then I hit "reassign".  But when my student opens the "reassigned" assignment, it's now blank and doesn't show any of their previous answers, nor my annotations to them.  Is there a way they can bring up the worksheet they already answered in and correct their answers to resubmit to me?  This would be especially needed for their guided notes assignments because I want to give them extra attempts to correct their errors so that they can use those notes for studying for their tests.  The only solutions I've found so far are super clunky: either I hit "reassign" after I leave them a comment with the numbers on the assignment that they need to redo (which means they next submit a mostly blank worksheet with only the corrected problems answered; problematic because they won't have a record of ALL THEIR OTHER ANSWERS to use as notes), or they download their original attempt as a PDF so they can see all my notes and highlights I left on their original attempt before completing just the parts of the worksheet they got wrong and resubmitting those (same problem as the first solution except now they have a pdf floating around somewhere on their computer with their original answers- we all know they'll never find that download themselves).    Am I missing a solution?