Join beams of different voices for guitar notation

Hi!
I'm currently working on a guitar transcription and I just cant find a way to join beams of different voices like it is presented in a lot of guitar sheets.

This is currently what I'm trying to do on my transcription:

As you can see there's two voices, that for easy reading reasons have both beams joined.

And this what I end up doing :

If anyone can help me I'll be more than grateful. Have a nice day!