Punch In takes not playing back...

The red circle with a bar indicates that the clip is muted.

Select the clip & press k to unmute

I do my punch ins a bit different than most folks here ...(I do believe)....

I don't use layers. 

If I have a mistake that needs fixing.... I split that mistake out of the track and it becomes a separate clip in the track. Then I highlight it and auto set my punch in/out point to that new clip. Then I delete the mistake audio. 
Next I simply record the part again...... no layers, no problems.  If I don't like any of the new takes, I can back up using undo while in that session. 

Be aware that undo will not undo if you close the project and come back later. 

My theory is and always has been, that if I played it correctly one time, I can easily do it again, and better the next time. 

So I don't sweat the loss of that clip. Just do it again, and again, and again, and again, until I am satisfied with the take. 

record, listen, analyze, delete, repeat..... until it's right.