Navicular Hairline Fracture - Suggestion

Dear Sir/Madam, 1 month back (26-Apr-24) when I was coming down through stair case, I got slipped and my left ankle got twisted, then I went ER and there doc didn't diagnose anything xray and given crepe bandage and pain killer for 1 week and advised to take 1 week rest. I followed it and then I started my daily activities after again pain triggered, observed mild swelling on mid food around arch area , doc told it would have been sprain, I continued my daily activities till 15-May-24 still swelling and pain wasnt subsided. then i took MRI. In MRI it has been noticed hairline fracture on navicular and little on talus. I went to 2nd doc on 25-May-24, and asked an advice what should be done, suggested that casting will not be helpful after 1 month. Suggested for 4 weeks non weight Bearing and Ankle brace will help with calcium supplement. My doubt in general how long it will take to heal hairline crack ? I read circulation will be poor for navicular in that case what should be taken