Premiere Audio stereo import changes into mono

Dear Community,

I have an .mp4 file with a stereo audio, when I importe the Clip in to Premiere it changes to a mono audio.

But just this clip. If I importe another clip with a stereo audio, it´s ok. So I asumed the Import Settings, but I have no clue what to change there...

Does anyone know what the matter may could be?

I´ll be really greatful if anyone can help me! Thanks a lot!

Best Regards