What is growing in the immediate vicinity? Any ivy?

Hi, there is nothing growing around it. Just this plant.

Well, something is growing somewhere. I had a neighbor with years of plumbing problems until she finally found that some daylilies growing along the back of her house had somehow grown their roots through/under the house wall and slab, then managed to invade her main drain pipe! If you’ve got daylilies growing there, I’d look them over very closely. Lol!

Based on what I see there, also look for honeysuckle vine nearby.

Your location might help narrow down possibilities.

Those look a bit like the roots I had to dig out of trumpet vine. I found them running dozens of feet away from the original plant.

I have knotweed and ivy on my property and don't believe it's knotweed. The inside of the root should be more orange. However, better safe than sorry. I would recommend cutting a few pieces off, at least 6", and trying to root in water glass or grow in soil (potted) to get a definitive answer.