Can we write any data over the written data of FF in stm32wb55

[RBG]

I am not able write anything once i write FF value into flash.

Does writing FF into erased area blocks the region from writing again till that page is erased?

[Tesla DeLorean]

You get a single opportunity to write data, and respective error ​correction bits. You get to pick the value you write, but only once after it is erased.