Issues with editing and exported photos

I recently did a shoot for a soccer/football game. And when I exported 2/3 photos from Lightroom they had some luminous static/grain on them in the final exported JPEG, this was also showing up in the develop module whilst editing. Initially I thought it was because my blacks were clipped/crushed - but when it showed up in my exported JPEG I began to think there is an issue with my LR (see attached image).

This would then disappear if I simply exported the photo again, but not making any additional edits. See this second image.

In the past, this issue would show up whilst I was editing a picture, and continues to do so till this day. But if I selected another picture and then back to the same picture, it would disappear. I thought it was my monitor, but now that it is showing on exported photos when viewing them outside of LR - I think there is an issue with my LR.

Anyone else experienced this? It is driving me crazy and I need help.

P.S I am using LR 12.5.1