No sound in VSE 2.82a Win10

Hello all,

I have been trying in vain to solve my problem for several days now and hope you can help me here.
I want to render an animation with Blender. Also with sound.
Unfortunately I don’t have sound in the Video Sequenze Editor, nor in the rendered animation.
I first rendered my animation as individual images, then inserted them into the VSE as a strip. After that, I inserted the MP3 audio files.

Already tried:
Change in the Preferences to SDL/OpenAL etc.
unmuted the individual strips
tried different containers

last settings:
file format: FFMPEG
container: Matroschka
video codec: H.264
audio codec: MP3

Blender version: 2.82a

I hope you can help me because I’m starting to go insane with this problem…

regards Fetti