@jonas you are a gem thank you so much!

@jonas Ah,thanks. My problem is solved as well now. Installing the Qt TLS Plugin again makes Strawberry scrobble again. Now, I can ditch Rhythmbox again!

Found a solution!

https://debianforum.de/forum/viewtopic.php?p=1358882#p1358665

Install all Pipewire packages

Create this file:
~/.config/pipewire/pipewire.conf.d/swapped_channels.conf

and paste this:

context.modules = [ { name = libpipewire-module-loopback args = { audio.position = [ FL FR ] capture.props = { media.class = Audio/Sink node.name = swapped_channels node.description = "Switched Channels" } playback.props = { node.name = swapped_channels node.description = "my-sink" audio.position = [ FR FL ] node.target = "Switched Channels" } } } ] Then Choose pulseaudio in strawberry in and Choose this device: Switched Channels