Open the nest into the Source Monitor. You should be able to remove it there.
And please, file a feature request to restore timeline clip marker functionality to what we previously had.
I wish it was that simple. I have tried everything I can think of to find this offender. It is not there.
The funny thing is it is only on the audio part of the clip, it is not on the video. I went so far as to open the file in audition to see if I somehow put one there and had it carry over.
I really wish there was a way in the main sequence to move to a clip marker on the nested sequence or to remove all markers on the clips in a sequence.
One question, do clip markers "rise up" to a sequence even when nested? So if I have a raw footage clip that I put a marker on through the source monitor, I know that it shows in its sequence, but will it show up on the sequence on the clip of the nested sequence? (hope that makes sense.)
You can test that just as easily as I.
Now I feel like a complete novice.