Slowing down Footage occurs duplicate frames

[m.stabentheiner]

Hello, 

I have a 50 FPS Footage which I like to slow down. I haven't any issues in the past, but now, Premiere duplicates the frames instead of correctly slowing it down. I have tried several steps:

Generating a sequenze out of the footage, change sequence settings to 25 FPS and slowing the footage down to 50% (Frame blending or optical flow), same issue.

Even when I interpret the footage to 25 FPS and generate a sequence out of it, I have the same issue. 

Not quiet sure, but it seems that the error occurs since the update 23.2, changed back to 23.1 with the same issue. 

Any Ideas or having the same issue?

[m.stabentheiner]

Update:

Found, that with a different footage, the workflow to interpret the file to 25 FPS worked, but slowing the 50 FPS footage down to 50%  still shows duplicate frames, same if slowing a 100FPS footage in a 50FPS timeline by 50%