Colored lines or hash-like artifacts in Lightroom are most often caused by the graphics system rather than an editing setting. The first thing to try is disabling Lightroom's graphics hardware acceleration/GPU option, restarting Lightroom, and checking whether the problem disappears. If it does, the likely cause is the video card or its driver.

If the issue remains, test whether the files themselves are damaged: send one of the affected files to someone else and ask them to open it on another computer. If they see the same corruption, the problem is likely in the image data rather than Lightroom. In that case, check the camera storage path first, especially the memory card, since failing cards can corrupt files.

Another useful test is to view/export the same image on a different graphics card or system. If the artifacts are gone there, that again points to the GPU/driver/monitor output path on your computer.

So the main troubleshooting steps are: disable GPU acceleration, update or test the graphics hardware, and verify the files on another machine to rule out file corruption.