Miles was fully possessed by Peter for less than an hour while Dani was possessed by Viola for over a decade before she returned to the lake and drowned herself.

Are Flora and Miles possessed?

As both Miles and Flora were possessed at some point by Peter and Rebecca respectively, they were both “tucked away” into their own memories while being possessed.

Why is miles so weird Bly Manor?

In addition to trying to keep their loved ones safe from Bly's Lady of the Lake, Flora and Miles are acting strangely because they're occasionally possessed by star-crossed lovers and former employees Rebecca Jessel (Tahirah Sharif) and Peter Quint (Oliver Jackson-Cohen).