Sound Forge is a multi-channel application, not to be confused with multi-track. You should be able to record to multiple channels though. Choose "New" in the 'File' menu and select the desired channels. SF is not designed for over-dubbing and mixing. Use Vegas for that.
btw, welcome to the Sound Forge group @ReKo-Kolu .
Thanks rraud. I noticed the info about the channel-track difference after I sent the question, but thanks for your confirmation. But when I choose new in the file menu like you adviced, I have only limited track selection available, not all the channels that are available on the interface. And that is confusing me.
What is "Limited track selections" I am not familiar with Sound Forge Audio Studio (AS) if that is what you are using.. nor have I recorded more than two-channels directly to SF Pro. You may want to contact Magix Tech Support