Sound from track 1 mixes with track 2

I’m recording a guitar in track 1 and a vocals in track 2. They are both mono tracks
The guitar track is on bus 'Ricardo1" - Input 1 and the vocals in on bus “Ricardo2” - input 2.
I recorded the guitar track
when I record the vocal track, I disable the monitor in track 1 and enable it in track 2 (it shows Yellow)
The problem is that the guitar track is mixing and recording along with the vocals, I can see in the mixer that all inputs are getting a signall in.

I first though the sound from my headphones would be mixing in, but even if I remove them, the sound from track 1 comes in super clear.
What am I doint wrong?
Any help would be greatly appreciated

What you are doing wrong is, you are not mentioning what hardware you are using. Steinberg UR something?
You certainly have a loopback enabled in your hardware. Plenty of posts in here.

Thanks, that worked!