Not Able to Monitor Track in Audacity 2.2.2

Sorry, as this inevitably a repeat question. But I am not able to get monitoring to work in 2.2.2. I can hear the existing tracks in my headphones, but cannot hear what I am recording. For example, I can hear the backing tracks but not the guitar I am recording, although I think my settings are correct. Is there some sort of glitch with this version? Thanks.

The setup for Overdubbing is > edit > preferences > recording: [_]Playthrough (Off), [X] Overdub (0n).

Then you set up your recording or microphone interface to play to your Headphones.

Most people can’t listen to their computer to overdub. Machine latency will just kill you. The live music will always be a little late.

That means your microphone, mixer or interface has to do it. It has to support “Zero Latency Monitoring.”

Such as this one.