This will of course alter the action of the streamer. If possible, you
should obtain the right hackles. This will solve your problems
immediately. Chinese or similar hackles are better than genetics, but
are becoming increasingly diffcult to obtain.

On many streamers, a small amount of lead wire added to the BUTT! of the
stremer will prevent it flipping, but also alters the action.

Using an underwing of bucktail will also solve the problem, ( Bucktail
is buoyant), without altering the action of the streamer much, indeed it
may well improve it, and prevent it flipping over. In this case you may
also use genetic hackles on the wings.

Lastly, the "flipping" action is sometimes highly desirable, as long as
the fly rights itself when retrieved, as this is typical of the
"flashing" behaviour displayed by many baitfish.

TL
MC