Ask HN: Strange Meandering Pixel? Dell U3415W 34-Inch

This is very strange.

This morning I began noticing what I first assumed was a very small insect meandering around on my screen. I quickly realized that it was not an insect after I tried to squish it (the dot just kept moving about).

I would describe this as a single pixel, that moves around my screen in a meandering fashion, very similar to how an insect moves.

My next thought was malware. I attempted a screen recording using Quicktime but was surprised to find that the meandering pixel did not show up in a screen recording. Hmm.

I was able to record it on my phone.

Any ideas what this could be?