Very sore spot after Tummy Tuck

I had abdominoplasty (extensive muscle repair without any liposuction) 5 months ago to correct a severe diastasis recti that was causing back pain and extreme abdominal weakness. Five months post-surgery, my abdomen finally is just beginning to feel more "normal" again, as persistent swelling is decreasing and some abdominal strength and sensation are returning. However, I am concerned about one localized, very sore spot just above and to the left of my navel, along the vertical line of permanent stitches that I can feel under my skin.

I first became aware of this spot approximately 1 month ago, a day after having slightly strained my abdominal muscles while pulling on the Spanx undergarment that I'm still wearing to support my muscles post-surgery. This sore spot feels like a small piece of suture material (perhaps a broken suture or the knot of a suture?) that moves slightly under my fingers when I touch the area. It is constantly sore and uncomfortable, and the pain increases if I touch the spot with my finger.

I am concerned about whether this sore spot means that my muscle repair is compromised and also whether the pain/uncomfortable sensation at this spot eventually will go away. When I asked my surgeon about this, she only said that what I am feeling is "a stitch" and that the pain may be due to a pulled muscle or muscle spasm and likely will resolve; she said the muscle repair is "probably OK" since my abdomen still appears flat and unchanged since the localized soreness began.