I noticed that this cutting is sending up a shoot from below the soil line. Any reason to be concerned about it?

Yes you should be very concerned!

You should be concerned because your cutting is now growing and it has roots!

In another words everything is fine.

sit back and enjoy!

No concern at all.

Like Michal said, Sit back and relax and enjoy the show!
That's the beauty of being a hobby gardener and these are the perks.

Good luck

Thanks, Montreal & Rafed--That's what I was hoping, but wasn't sure.

This happens alot, Don't worry about anything. Good work. Ciao

Thanks--nice to see your posts again!

Ken, there are some times when the "underground" shoot will rot or mold, but generally they eventually find their way out, and are just fine. Two healthy nodes pushing growth is a better option than two defective nodes doing nothing.