Keyboard volume drops out after first chord

I’m using Audacity version 2.3.2.
I’ve recorded two tracks, acoustic guitar and vocal with no problem.
When adding track 3 with a keyboard using the strings option the volume drops out when i change to the second chord.
I’ve tried adjusting all the volumes in settings, keyboard and Audacity but nothing seems to work.

What happens if you record guitar as a third track?
What happens if you record the keyboard part on its own in a new empty project?

How is the keyboard connected to your computer?

I recorded the guitar on track three and no problems.
I recorded the keyboard on a new project ( track 1 ) and the same problem, no volume after first chord.
The keyboard is connected through the microphone port using a standard lead and an adapter.

I’m guessing that if you change the keyboard sound to a percussive instrument, such as a marimba sound, the problem goes away.

Yes. I recorded a preset drum sound with no problems. I’ve had a word with a friend who has used this program and he had to use a USB connector with his keyboard. That’s next on my list.

In that case, it’s almost certainly an “effect” in your computer sound system (probably “echo cancellation” or “noise suppression” or similar).
Go into the Windows Sound settings and disable all “Enhancements” (See: