F-1 is independent of I-485 filing and good until it ends, if you don't leave USA and not use EAD (based on I-485 pending).
But OPT may have a risk (somewhat high, but not necessary) of denial if I-485 has filed, even if you maintain F1 status.
But OPT may have a risk (somewhat high, but not necessary) of denial if I-485 has filed, even if you maintain F1 status.