F1 Visa Defer admission in US schools. I20, Visa issues

Hi, I got my initial I-20 for Spring 2021 with start date of 1/13/2021. However, I am planning to defer this semester and get a new I20 issued with future program start dates. The problem is that I already got F1 visa issued to me on the first I20 that I got that was for Spring 2021 start date of 1/13/2021. If I request to reissue my initial I20 for future program start date, will the SEVIS ID on my I20 ? Most importantly, do I have to reapply for my visa ?

Please suggest what to do/what steps to take.