Depends on the kind of FD.
If it is an FD that automatically breaks if you withdraw cash, it is just like cash in savings but earns a larger interest if you don’t withdraw. e.g. My bank (ICICI) does this, creates FDs that give a higher rate of interest, but if I withdraw more cash, they are broken and I lose the additional interest.
I can ask them to not create auto-FD sweep (have done it before).